I need to mention I mixed up Ray Carlsen and Paul Carlson with the cap removal method. (Paul is the one I got the removal method from) I'm fully aware they are two different people :-)
the vinegar will most likely eventually dissolve the salts if you leave it long enough, like 2-3 hours, but you might need to submerge it in the vinegar because just the amount that you can spread on it will alter in PH pretty quickly in the localized areas near the heavily salted areas
@@briangoldberg4439 I don't think they are necisarily salts. They may be lead/tin oxides. Both are used as white/ off white pigments in artists paints. The vinegar works on the unreduced electrolyte (Possibly KOH) put not on the metal oxides. The brown stuff is possibly breakdown products of the solder mask and the electrolyte. May wash off with acetone or Paul Carlson's favourite, Laquer Thinner.
The secret to white vinegar cleaning is to float the board like you did and then wait while doing nothing to the board for 10 to 12 minutes then use a electric tooth brush, one of those Sonic ones, to clean corroded areas. The electric tooth brush is important and essentially acts like a localized ultra sonic cleaner when combined with the vinegar. This method can clean some really badly green corroded stuff and that white stuff you encountered is an indication that it was working but was not completely removed. Also, and I’m not sure if it matters but I use IPA with the same tooth brush to clean up after the vinegar rather than water not sure if that is necessary but might be part of why I don’t end up with any of that white after cleaning residue. Further, be aware that the white vinegar will dull the luster of non corroded solder joints so it’s best if you can restrict where you, float vinegar, on the board to only the areas that have corrosion issues. I use a syringe to better control where the vinegar ends up.
ingenious tip. Thanks! My dad was a watchmaker, and he had an ultrasonic cleaner from the '60s with many moving parts, which was seemingly always in use (and what a gadget that was) but he used to talk (semi-ironically) about "infrasonic" cleaning, which was usually meant he was going to be agitating the part by hand in a big bowl while it was immersed in soapy water :)
I just wanted to comment, that after these Mac-Repair-A-Thon i finally was "brave" enough to do my first recap of a Mac Classic. I was using your or Pauls removal method with 100% success at all Caps. I don't want to show anyone my solder-joints but they are all strong soldered to the pads and have contact. And the loudspeaker is working again. And so on. So thanks for your virtual empowerment so to say!
The screen is supposed to "look squished", since the pixels are supposed to be square, not stretched to fill the screen. The idea was to have true WYSIWYG so that you could draw (or write) on the display using apps and get true 1:1 (to scale) of what you print. Also worked wonders on modeling stuff you could hold against the screen while you copy the dimensions into the drawing or other modeling app. Apple's stand-alone CRT's were also like that up until the Multiple Scan AV stuff. That's one of the reasons the 12" RGB had a different resolution (512x384) from the 13" RGB (640x480). Since the 512x342 resolution of the 9" CRT isn't 4:3 aspect ratio, but rather a very close approximation of 3:2, there's bigger black borders on the top and bottom than the sides.
The bubbling is acid-base neutralization, which releases carbon dioxide and leaves behind a salt (not salt as in table salt, but A salt depending on the exact reactants). A wash after is a good idea because of that.
Ceramic also don't work well in audio devices. Repaired a receiver once, that had a cap that will 100% fail at one point, because the voltage was too exact for its use case instead of a little over, which is important for components in the standby circuit because there is a higher chance of voltage spikes. The issue was then, that the cap with the higher voltage was not available in the needed size, so I tried a ceramic first. The device was working but a relais started clicking, so I replaced it with an old foil cap that was lying around, because they had longer legs to bend around and the issue was gone.
The wiggle method for the caps is fine. I sometimes repair old ecu's of 90's cars and those circuit boards tripple layerd sometimes more. So pulling them out saves the board and is way easyer to repair without damaging the circuits. Nice job!
The white/yellow crust left behind is oxidized capacitor electrolyte. I've found that CRC Lectra Clean works best to remove capacitor electrolyte. Just hose the area of the board down with the electrolyte, scrub it, then hose it down again with the board at an angle. It'll take all of the electrolyte off with it. IPA instantly oxidizes capacitor electrolyte, which is what the white streaking is that gets left behind, and makes it harder to clean.
Don't let the loud few complaining about the wiggle method or however you remove the caps. You've proven you know what you're doing, but some people will complain no matter what. The loud few shouldn't get so much attention is my opinion :)
There is certainly a risk to each method of removal (removal itself has a risk regardless). Just pick the amount of risk you are comfortable with. If you don't want to apply mechanical stress then use hot air or whatever else.
It's gone? Yes. Then where is the freakin problem? Cause he didn't removed them another way? We are adults or toddlers fighting because he didn't lick his lolipop same way we are licking ours?
Try using a solution of baking soda on the cap electrolyte residues, the average electrolytic capacitor uses a mild acidic stuff as their electrolyte, and rinsing off with acids such as vinegar or citric acid doesn't do much, those are better suited to battery leakage where the electrolyte is basic (aka Alkaline), so for caps that did the dirty, a basic solution needs to be used to neutralise the goo... :)
Someone mentioned vinegar first, then baking soda, but maybe you're right with just baking soda. The other person explained their reasoning as a supposed chemist, but I don't know either way.
@@robinsutcliffe-video_art The Wikipedia article on the "capacitor plague" at the bottom (in the "Investigation" section) says that the good Japanese caps are/were acidic and the failing Taiwanese caps were alkaline. So caps seem to be acidic (assuming that you aren't working with "capacitor plague" formula caps) as long as the article is correct.
I recently re-capped a LCIII motherboard and had the white residue as well. What worked for me was several passes of IPA, brushing and rinsing with water. You really need to rinse off the IPA residue each time to really get rid of it. Love your videos!
You can use a waterpik (It's just like a mini power washer) to clean under the ic's. You can spray right underneath them to flush them clean of acids etc.
Adrian, for scrubbing those pads, I would REALLY recommend a fiberglass pen. It's basically just a pen with fiberglass bristles coming out the tip. It's a great way to scrub, without damaging, pads and circuit boards when you've had stubborn residue from leaky caps like that.
Hi Adrian. Try giving the board a wash with both vinegar AND baking soda (not at the same time, one after the other). This way you have a chance to remove the electrolyte with either an acid (vinegar) or a base (baking soda). This is helpful for (NiCad or NiMH) battery corrosion, too, plus the baking soda solution will help neutralize any vinegar still hiding under IC pins! Then finish off with distilled water or IPA and let dry. Hopefully, this will take care of the formation of that white salty crap. 😀
Many capacitor electrolyte is a base, so vinegar helps neutralize it, stop its reaction before cleaning, which helps ensure that anything missed during cleaning doesn't continue to eat at components.
Electrolyte can be either acidic or basic. I don't know how you can tell which ones use which type, but use vinegar (rinse thoroughly after!) and then baking soda (as a paste when mixed with water) should do the job of completely neutralizing all capacitor pee.
Electrolyte in car batteries is acid. Nicad,Nimh and capacitors its a BASE. so you clean a base with acid(Vinegar). then clean with distilled water(tap water has minerals,flouride etc which is bad). then Isopropyl alcohol.
Even if you are going to sonic clean it is good to use the vinegar to neutralise the electrolyte before cleaning. The dodgy Electrolytic capacitors were conterfeit name brand caps, I have even seen OEM intel boards with these dodgy caps.
I've removed countless caps with the twist method after using hot air, iron(s), cutting, and about every other method you can think of. +1 for twisting for the win. Regarding the corrosion/salt leftover, it's probably overkill, but I sometimes just use hot air/flux to remove the offending IC, soak it in IPA while cleaning the board, and then sold back on the board. Time consuming, but leave it looking brand new in most cases. Take care!
That's exactly what I do and it's not overkill at all. That's what you're supposed to do. Leaving that salt on there does absolutely no good to the legs of chips.
i think that vinegar reacts with the electrolite (i suppose it's usually basic, like bactery residue), so it becomes neutral (aka not corrosive) of course you have to remove all the vinegar or it's the same thing
great job mate. I also adopt similar method as you for repairs of classics. out of mixture of 7 classics and SE's, i have managed to salvage 4. did trace repair on one. the other 3 have logic boards too far corroded. i dont have any more hair to lose on those. Trace repairs can be very rewarding when you nail it but so time consuming. I enjoy your content very much. bravo brother !
I also had some motherboard issues after recapping, but with the classic II. I noticed it was inconsistent when booting up, and if I wiggled the motherboard while it was on, the screen would turn to garbage. I asked around the forums and they said it was cracked solder joints, which I thought made sense. I couldn't pin down the exact joints that were cracked, so I just ran my heat gun across the entire board. I ended up solving that problem, and my Mac could boot consistently.
Their were so many counterfeit caps back then. I have devices that are 50-70 years old and the caps are fine, but stuff from the 80's, 90's, early 2k.... I also worked in manufacturing in the late 90's and we got several batches of parts that had to be returned because they failed testing, they were name brand, but when you looked close the heat shrink labeling was different, harder to read.
What I’ve found to be very effective for removing the white salt stuff from between the legs of surface mount devices is soda blasting. I use a cheap sand blaster with a built in plastic reservoir and dump a box of baking soda in the top. It removes the residue without stripping off plating or silk screen markings.
I bought a used Classic II back in 1993 and I still have it. I found a retro hobbyist to recap it for me so it works again. He said it was the hardest job he ever took on. We even got the files off the old SCSI hard drive. The irony is that I had an SE for a while but sold it believing that the Classic II was an upgrade. I wish I hadn't done that now.
I would wash the board afterwards in a dishwasher. Seriously, boards are put through a dishwasher after the wave solder process and then air dried using compressed air. This will clean up the board and the compressed air will push the water out from under the components. As always, ensure the board is completely dry before doing any work on it. I worked in board touch-up and repair for a number of years prior to moving on to the more interesting and more satisfying testing and repair. I recommend using a burnishing pen instead of something sharp to clean the pads. That will clean the pads safely without the chance of hitting an attached etch by mistake. Electrolytics are used for specific reasons such as better filtering and not necessarily for cost. Have you ever thought of setting up a test setup? Take a known-good chassis and extend the power cables and cables for the CRT and connect that to an accessible power supply with cables for the motherboard. This will allow for easier testing and troubleshooting without needing to reconnecting the unit up again to test the boards. When I was a bench-tech we had setups like this for the various products and it made testing a whole lot easier.
*good* vinegar or lemon juice are essential when you are dealing with capacitor leakage, just washing the board does not neutralize the acid and it keeps eating away on the board
Hi Adrian, the vinegar is not for cleaning of electrolyte but for neutralizing it, preventing it doing more damage. The bubbling you see thats the chemical reaction you want. Its really good idea to put vinegar each time you have battery spill.
Hi Adrian, I had similar problems with memory and leaking caps on my classic. After recapping computer was alive, but memory expansion was not detected (no sad mac this time). The problem was solved by desoldering UH6 (74LS174) cleaning acid under the IC legs and soldering a new one. But another problem remained, I could no format or save to disk, and this time was the adjacent IC UI6 (74LS368) with one trace broken under it by corrosion. I bypassed this broken trace with a bit of thin cable and solved... so take a look at this IC because they are very near some of the leaking caps. And finally about the original hd, when they seem don't boot, you only need to open them and remove a little rubber black ring where head sit that gets sticky. Hope it helps, Francisco
Many of these have died via Battery leaks and capacitor corrosion. I had two. I put both away for a move, then the batteries blew and destroyed the ICs. Ate the legs of the VLSI chips.
When we had the leaking caps issues in the early 2000s. We noticed a pattern on the top of the caps. The ones with a square cross leaked but the ones with. An offset K on top were always fine. So we were at that time in the lookout for the crappy cross caps and happy if a system had “K caps”
I've found that when you need to clean corrosion off of pads (or off of chip legs in a bad situation) , a fiberglass scratch pen does it quickly and easily. I have an A4000 which was sold to me as a known basketcase...the original owner didn't think it was savable, so I got it for a steal. I had to recap it, replace all of the clock circuitry, replace all of the simm sockets, and replace the F245 bus transceiver chip which is located right next to the clock circuit (which is also connected to on-board fast memory). All of it was corroded from a leaky battery. I've gone through a couple of those fiberglass scratch pens, and they are literal magic.
Rather than scratching the pads I've found that when using the solder braid/wick it cleans up much better if you use MG Chemicals liquid no clean flux you won't have that black residue.
Note that many/most kinds of flux _are_ corrosive to some degree, or can attract corrosive things to the motherboard. It's recommended to clean off anything except "no clean" flux, and there's no harm in cleaning that off either if you want a better appearance.
Differnet type of capacitor, especially early 90s is mostly due to capacitance available at the time, MLCC ceramic capacitor that can go into high capacitance did not exists back in the day, else that's what they would have used instead of SMD electrolytic or tantalum. As for MLCC, the literature seems to say the opposite, the closer to rated voltage the more loss, the lower the DC voltage the less loss in capacitance (but the amount of loss will depends on the type of MLCC capacitor) And I didn't knew that, so, I've learned something new today 😊
12:20 the electrolyte is alkaline (basic), and the vinegar is acid, so they react and produce carbon dioxide. It neutralises the gunk so it can't continue eating away at the metal, and there is less left to form salt crystals when you wash it later.
Using dual iron or even tweezers I used to get a pad or two come off of every other board. Since switching to the twist method I've had no issues at all. Anecdotal but that's my experience. Also, on that analog board you'll get that fishy smell on almost every single electrolytic on there. It'll still work OK without replacing them but I definitely swapped them all out on my Classic and it runs great!
12:00. I buy cleaning vinegar for stuff like this. You can put the metal contacts from a tv remote control or kids toy into a little jar and it will neutralize the battery acid and corrosion within minutes.
17:23 , well that is more or less like limestone, same happens to washing machine, there are some products to put on the washing machine to remove the same stuff, the problem is I do not know how hard/rough will be on the board (because the washing machine inside is basically stainless steel.
By the way! I recommend trying to use liquid instead of alcohol to clean the throttle or carburetor dampers of the car. It also perfectly cleans soldering mud with a gun flushing liquid from construction foam. However, in this case it will be necessary to be more careful with plastic products, as they can be damaged.
Also of note, ammonium perborate is itself weakly acidic, so hitting it with another acid is likely not the best idea. You need a weak base which is easily washed away, else you risk producing new acids which might cling to the underside of chips regardless of how much you wash.
The flux breaks down the oxides and avoids oxidation of the tin. It also helps the tin to wet the surface by acting as a kind of surfactant. Also There are fluxes that ain't no-clean (i guess Adrian does know very well, but young players might get into this trap). To be safe, always check the data sheet (and use a flux from a trustworthy source, if possible).
I make sure to check all electrolytic capacitors with a capacitor meter. I recommend doing this procedure with old and even new parts. Marriage, alas, also occurs. It is better to put Low esr capacitors on the power supply circuits, since they work more efficiently. In those years, these were not produced yet. Instead of surface-mounted capacitors, I put ordinary ones on my Amiga 1200, with terminals suitable in size. There is enough space and soldering is very convenient.
The vinegar reacts to the electrolyte and stops the corrosion, you don't need to scrub, just let the vinegar do it's job. It is always a good measure to use vinegar on boards that had some kind of leak from batteries, caps or even if they are rusty.
Arf, I was secretly hoping you would get a sad mac 0000000F 0000000A like I have so I could follow along to sort out my issue 😂 looking forward to see the resolve of 00000005 anyway. Never know what I could face next 😂 already excited about part 3 👍
I think it is interesting that you push the pins for the analog board fom the inside. you can get your fingernails under them from the outside and pull them up and out.
I teach life science. A couple years ago I moved into a new lab - in the cabinets I found 15 Mac’s just like this. Had the IT department take them away….. were probably barely used. Maybe a couple labs periods a year for less than 10 years…. Then abandoned in the cabinets.
By the way, you can put a mathematical coprocessor by installing it on top of the main adapter with a panel on the handkerchief, as they do on the Amiga when it is not possible to connect to the address and data bus.They actually work in parallel if you look at the scheme with a difference in a pair of signals.
Vinegar only neutralizes the corrosion. You still have to clean everything up and apply new solder to everything. You should never leave that white salty stuff on the boards, that's neutralized electrolyte and can still cause issues. You have to completely remove the old solder and apply new solder after cleaning the pins and solder pads. Otherwise you'll have loads of issues in the future.
All Mac Classics did not come with that RAM board. To meet their under $1K price, the base model came with 1M only (no board). That little RAM board has 1M on it and two slots. So if you see one with 2M, then it has that board. I believe it sold with 1M (no board) or 2M (The 2M version came with a Hard Drive, the 1M didn't.). I don't recall if Apple sold a 4M version. I don't think so...
Tantalum caps have extremely low ESR and if the circuit they are in is not properly designed, inrush current will cause them to fail (and they usually fail shorted).
The powdery residue that is left behind when you cleaned the electrolyte corrosion from the caps is hydrogen. It's the same stuff that batteries produce when they rupture or if you left a light on in your car over night. Additionally I'm not sure why anyone would recommend vinegar since that is an acid. A base like baking soda or powder would be better to neutralize the electrolyte chemicals from leaking capacitors. Perhaps a combo of two would be best (neutralize with baking soda/powder then use vinegar) Certainly using IPA as you have shown many times does a good job for a final wash.
Vinegar simply converts insoluble boric acid salts (electrolyte) into soluble acetic acid salts so they can be washed off. Acetic acid is not so corrosive to damage the board in 20-30 minutes. Remember that alcohol reduces the solubility of acetates. So use water.
All that board flopping around the neck of that tube was making me nervous. It’s easy to remove those couple cables and connectors and the anode is no big deal!
Yes, I have seen Paul Carlson's (Mr. Carlson's Lab) video about this. Mr. C has incredible knowledge and experience - I'd totally trust any method he demonstrates.
As usual, great video! Yes, Mr. Carlson has some great info and expert knowledge - as do you 🙂 Your Commodore 64 videos saved me sooooo much time on my last restore! I started using the wiggle method years ago to get those caps off and never had an issue with damaging traces (easy does it!). I've found that baking soda and IPA with a soft brush works great to clean up most of what you find on old circuit boards. Do you also test caps that aren't visibly leaking with an ESR meter to verify good/bad caps or do you strictly go by leaking = bad & not leaking = good? I occasionally find a bad cap that looks clean and not bulging. Looking forward to your next video!
Vinegar is useful where Varta batteries have spewed their goo. For the electrolyte problem, you might try a petroleum based solvent (e.g., WD-40) followed by an alcohol or QD contact cleaner rinse (for simple vapor degreasing).
Tip for soldering the caps on that large copper plane.... your struggling because your not waiting for it to heat the boards massive copper track, just wait till you see it start to flow then add solder as needed..
6 місяців тому+1
Adrian I just love how you use the wiggle method and dont give and F about what people think. I also learned about the method a few years ago from Mr Carlson's Lab, there are other videos and sources to. My version of it is to always push, and twist until I feel resistant then twist the other way, takes a little longer but never failed and I used it for like 2 years before I got a hot air station. And in some cases where the cap is 1mm away from plastic connectors it might be the only way to get to it. I remember how much flack I got on my then 300 sub YT channel when I did it the first time, its funny how a small YT gets flack, a 1000x bigger one gets applause doing the same thing! I had people claiming to have degrees in engineering and certificates and crap claiming how I was killing the pads and people unsubed and told me how dumb I was 😆 I made it very clear in my video also not to pull but push, you want the leg to break as Adrian is saying, but yea people still accused me of pulling even after a written explanation. Some people just cant accept some ways of doing things that they must insist reality is something else then was what shown and sad in a video. I also had people telling me one should not solder on corrosion and yea its not ideal, there argument is that the joints will fail. But I see pros clean up corrosion all the time with the iron or hot air like Louis Rossmann. So if I was to listen to the wiggle haters and the "dont solder corrosion" then how the hell am I gonna get the SMD caps off? 🤣 Anyways I seen many videos where people after ripping pads, because most people will try the solder iron and lift method, this LIFTS pads, but people seems to not get that. A pad is very strong along the axis of the PCB but it week on the Z axis so trying to lift caps is like pealing tape of the desk, bad idea. But what I seen is then they try the wiggle method and has no issues getting old caps off. Also a ripped pad for ANY reason can be fixed in many ways, repair kits even exist if you dont want a wire and some solder mask. Anyways people get way to upset over how people repair there stuff, its just some caps and pads, it can be fixed.
The chemical in capacitors is apparently ammonium perborate. My first thought was that the bubbles were just CO2 like when you use vinegar on leaked batteries. But that doesn't necessarily explain what's happening here. You might be getting gaseous ammonia! I will investigate. You might also be producing small amounts of hydrochloric acid which would be BAD. If you really douse a board like this you have to wash it like crazy after.
Always disconnect the flyback transformer! Never trust the bleed down resistor. Then ground the tube so the ambient charge it builds up cannot shock you. Source: I used to work at apple and still remember those electricity cooks your veins videos from training.
After useing a solvant with any concerning level of watter on a board i think pouring or spraying something like 90+% Isopropyl Alcohol on the board to mix with remaing watter wich should borh dilute the watter and evaperat the watter much quicker sence IPA evaporates quick.
I don't think I would be comfortable placing a motherboard in an ultrasonic cleaner. I would be too afraid of the vibration damaging the bond wires inside the IC chips. Bil Herd did a fantastic talk about component aging and failure, and he mentioned vibrations and failures.
Regarding the Mac LC, while considerations regarding market segments would have probably been a thing, there is also a real reason behind this market segmentation: 16-bit boards and their various components were just cheaper, helping with the low price point. (Compare the i8088, used for the same reasons in the 16-bit era, since 8-bit boards were significantly cheaper, or the original Mac board vs. the Lisa. Consumer computers were never about what could be made at the state of art, but what could be made to a certain price point. It may be more than a coincidence that "computer" is spelled with a "c" as in "compromised"…)
Glacial acetic acid is free of process derivatives, aka sugars and pulp. Its generally not a big deal if you buy the heinz white vinegar, but some may prefer it.
I just got some guts and wiggle-method removed all the caps from my mac classic board. I had been waiting for years but was too afraid! No longer! Just ordered some tantalums. I suppose I will have to look at the psu, too.
Tantalum caps are sometimes expensive, yes. I replaced all the ones on my IBM PC/XT/AT series, and the cards within. Some of them were STUPID expensive for their size. Over a buck apiece for 22uF? C'mon.... So yeah, that's probably why electrolytic were more common.
Consider using/buying an ESR meter to test the caps. They even work in circuit and are a must have tool for troubleshooting and general maintenance. It can detect failing caps before they leak or bulge
If I remember, the problem with 90's capacitors is due to corporate espionage gone bad. If I remember the news at the time, some Chinese manufacturer stole the electrolyte formula from a major manufacturer, but they botched the recipe, so capacitors manufactured with that formula all leak and fail over time. Unfortunately, before the news broke and everybody found out, they sold millions of capacitors as counterfeits of all the major brands, and manufacturers everywhere bought them, thinking they were getting good quality and discount prices. And we're still suffering the aftermath of that mess today.
Yesterday I recapped my Macintosh Classic with fresh tantalums and my process wasn't too different from what you showed here. In my case though, one of the vias in-between the central caps has been completely eaten away by the corrosion, so I had to solder a wire onto the nearby trace and onto the remaining pad on the other side of the board to restore continuity. Fortunately that did the trick and the Mac Classic is now working perfectly again. I will have to take a look at the analog board sooner or later. Right now there doesn't seem to be any sign of leaking or corrosion, but I can't quite make out the series of Nichicon caps that are on there, so it's a bit too early to celebrate I think. Good to know what to look out for, in any case. That reminds me, did you happen to take note of the markings on the board next to the six capacitors that you removed? The console5 tech wiki lists all of the various capacitor types on the analog board, but I don't know exactly which ones are the brown Nichicon caps.
I'm not sure if the black gunk youre seeing is coming from the caps. It looks like the rosin flux that's in the center of the solder and also used in the solder braid. I get that a lot at work. Usually just IPA and some cotton swabs and it cleans right up
Vinegar is mostly to neutralize any alcaline solution. I works on the iquid of some caps and batteries, but mostly to prevent further corrosion by turning the alkali into a salt. To eliminate the salt residue, you need to know what exactly goes into those caps/batteries and, after neutralizing the spillage (you may need to use a different reagent, like ammonia, depending on the specific leaky component), use the correct solvent (e.g. water, alcohol, acetone, a table salt solution, a coppersulphate solution, a rust remover, etc.)
In my experience, vinegar works really really well with battery electrolyte. Alkaline goo is especially good to use vinegar on. It’s stunningly effective, I use it all the time when restoring old toys. Glancing through some literature, caps can be acidic or basic or neutral, so a bicarbonate solution may also be good. You’ll want to throughly rinse between the vinegar and bicarbonate though.
I need to mention I mixed up Ray Carlsen and Paul Carlson with the cap removal method. (Paul is the one I got the removal method from) I'm fully aware they are two different people :-)
That's what I thought.
the vinegar will most likely eventually dissolve the salts if you leave it long enough, like 2-3 hours, but you might need to submerge it in the vinegar because just the amount that you can spread on it will alter in PH pretty quickly in the localized areas near the heavily salted areas
@@briangoldberg4439 I don't think they are necisarily salts. They may be lead/tin oxides. Both are used as white/ off white pigments in artists paints. The vinegar works on the unreduced electrolyte (Possibly KOH) put not on the metal oxides. The brown stuff is possibly breakdown products of the solder mask and the electrolyte. May wash off with acetone or Paul Carlson's favourite, Laquer Thinner.
LOL, I didn't even know his first name!
The secret to white vinegar cleaning is to float the board like you did and then wait while doing nothing to the board for 10 to 12 minutes then use a electric tooth brush, one of those Sonic ones, to clean corroded areas. The electric tooth brush is important and essentially acts like a localized ultra sonic cleaner when combined with the vinegar. This method can clean some really badly green corroded stuff and that white stuff you encountered is an indication that it was working but was not completely removed. Also, and I’m not sure if it matters but I use IPA with the same tooth brush to clean up after the vinegar rather than water not sure if that is necessary but might be part of why I don’t end up with any of that white after cleaning residue. Further, be aware that the white vinegar will dull the luster of non corroded solder joints so it’s best if you can restrict where you, float vinegar, on the board to only the areas that have corrosion issues. I use a syringe to better control where the vinegar ends up.
oh this sounds like a very cool idea! Thanks for recommending, I'll definitely give that a go!
Nice I have never thought of using one those tooth brushes !
ingenious tip. Thanks!
My dad was a watchmaker, and he had an ultrasonic cleaner from the '60s with many moving parts, which was seemingly always in use (and what a gadget that was) but he used to talk (semi-ironically) about "infrasonic" cleaning, which was usually meant he was going to be agitating the part by hand in a big bowl while it was immersed in soapy water :)
Vinegar always goes well with chips!
is not real vinegar, more like battery acid.. real vinegar make them soggy and it don't have a pronounced taste..
@@docwhogr😂😂😂😂😂😂😂
I just wanted to comment, that after these Mac-Repair-A-Thon i finally was "brave" enough to do my first recap of a Mac Classic. I was using your or Pauls removal method with 100% success at all Caps. I don't want to show anyone my solder-joints but they are all strong soldered to the pads and have contact. And the loudspeaker is working again. And so on. So thanks for your virtual empowerment so to say!
(Of coure i tried before on old spare cheap pci-cards before the mac classic mainboard!)
The screen is supposed to "look squished", since the pixels are supposed to be square, not stretched to fill the screen. The idea was to have true WYSIWYG so that you could draw (or write) on the display using apps and get true 1:1 (to scale) of what you print. Also worked wonders on modeling stuff you could hold against the screen while you copy the dimensions into the drawing or other modeling app. Apple's stand-alone CRT's were also like that up until the Multiple Scan AV stuff. That's one of the reasons the 12" RGB had a different resolution (512x384) from the 13" RGB (640x480). Since the 512x342 resolution of the 9" CRT isn't 4:3 aspect ratio, but rather a very close approximation of 3:2, there's bigger black borders on the top and bottom than the sides.
I've had a whole bag of un-used brown caps leak on the shelf. They are a problem for sure. Yes, the 90's capacitor plague, I remember it well.
yeah, old age is there biggest enemy for sure.🤣🤣🤣🤣🤣
The bubbling is acid-base neutralization, which releases carbon dioxide and leaves behind a salt (not salt as in table salt, but A salt depending on the exact reactants). A wash after is a good idea because of that.
A wash is necessary anyway as you don't want to leave corroding acid on the board and within the components.
This is my fourite "Recapping Channel" watching you Adrian is crazy soothing somehow. Look forward to part 3. Cheers
does the wiggle method drive you bonkers?🤣🤣🤣
Ceramic also don't work well in audio devices. Repaired a receiver once, that had a cap that will 100% fail at one point, because the voltage was too exact for its use case instead of a little over, which is important for components in the standby circuit because there is a higher chance of voltage spikes. The issue was then, that the cap with the higher voltage was not available in the needed size, so I tried a ceramic first. The device was working but a relais started clicking, so I replaced it with an old foil cap that was lying around, because they had longer legs to bend around and the issue was gone.
The wiggle method for the caps is fine. I sometimes repair old ecu's of 90's cars and those circuit boards tripple layerd sometimes more. So pulling them out saves the board and is way easyer to repair without damaging the circuits. Nice job!
The white/yellow crust left behind is oxidized capacitor electrolyte.
I've found that CRC Lectra Clean works best to remove capacitor electrolyte. Just hose the area of the board down with the electrolyte, scrub it, then hose it down again with the board at an angle. It'll take all of the electrolyte off with it. IPA instantly oxidizes capacitor electrolyte, which is what the white streaking is that gets left behind, and makes it harder to clean.
A tip I've learned when using solder wick is to put some flux on the braid to help the solder flow to the braid better.
You can purchase wick with flow already in it, at least the one I have here has.
That's what i think too. To big iron tip for smd for my taste.
@@adilsongoliveirathough much like with solder, for tricky use cases the built in flux isn’t always enough
Don't let the loud few complaining about the wiggle method or however you remove the caps. You've proven you know what you're doing, but some people will complain no matter what. The loud few shouldn't get so much attention is my opinion :)
100% THIS
Agreed. Just ignore them dude.
Quickest and easiest way to do it
There is certainly a risk to each method of removal (removal itself has a risk regardless).
Just pick the amount of risk you are comfortable with. If you don't want to apply mechanical stress then use hot air or whatever else.
It's gone? Yes.
Then where is the freakin problem?
Cause he didn't removed them another way?
We are adults or toddlers fighting because he didn't lick his lolipop same way we are licking ours?
Try using a solution of baking soda on the cap electrolyte residues, the average electrolytic capacitor uses a mild acidic stuff as their electrolyte, and rinsing off with acids such as vinegar or citric acid doesn't do much, those are better suited to battery leakage where the electrolyte is basic (aka Alkaline), so for caps that did the dirty, a basic solution needs to be used to neutralise the goo... :)
also worthy of note is that chemical reactions can be accelerated by increasing the temperature.
Someone mentioned vinegar first, then baking soda, but maybe you're right with just baking soda. The other person explained their reasoning as a supposed chemist, but I don't know either way.
caps are alkaline which is why vinegar neutralises the leaked effluent@@Loki-
@@robinsutcliffe-video_art The Wikipedia article on the "capacitor plague" at the bottom (in the "Investigation" section) says that the good Japanese caps are/were acidic and the failing Taiwanese caps were alkaline. So caps seem to be acidic (assuming that you aren't working with "capacitor plague" formula caps) as long as the article is correct.
I recently re-capped a LCIII motherboard and had the white residue as well. What worked for me was several passes of IPA, brushing and rinsing with water. You really need to rinse off the IPA residue each time to really get rid of it. Love your videos!
You can use a waterpik (It's just like a mini power washer) to clean under the ic's. You can spray right underneath them to flush them clean of acids etc.
great idea brother! if you put vinegar into water pik even better!
I have a spare one of them great idea
Adrian, for scrubbing those pads, I would REALLY recommend a fiberglass pen. It's basically just a pen with fiberglass bristles coming out the tip. It's a great way to scrub, without damaging, pads and circuit boards when you've had stubborn residue from leaky caps like that.
Hi Adrian. Try giving the board a wash with both vinegar AND baking soda (not at the same time, one after the other). This way you have a chance to remove the electrolyte with either an acid (vinegar) or a base (baking soda). This is helpful for (NiCad or NiMH) battery corrosion, too, plus the baking soda solution will help neutralize any vinegar still hiding under IC pins! Then finish off with distilled water or IPA and let dry. Hopefully, this will take care of the formation of that white salty crap. 😀
So vinegar, then baking soda and vinegar solution?
@Bassquake76 no he meant vinegar first. Then baking soda only. If you mix vinegar and baking soda they'll just fiz and neutralise each other
Many capacitor electrolyte is a base, so vinegar helps neutralize it, stop its reaction before cleaning, which helps ensure that anything missed during cleaning doesn't continue to eat at components.
@@martykopka How do you remove the baking soda powder? Rub it on then blast it off with compressed air?
@@Bassquake76 water, distilled water or IPA. Then let dry.
Electrolyte can be either acidic or basic. I don't know how you can tell which ones use which type, but use vinegar (rinse thoroughly after!) and then baking soda (as a paste when mixed with water) should do the job of completely neutralizing all capacitor pee.
Electrolyte in car batteries is acid. Nicad,Nimh and capacitors its a BASE. so you clean a base with acid(Vinegar). then clean with distilled water(tap water has minerals,flouride etc which is bad). then Isopropyl alcohol.
Use a fiberglass pen after your cleaning to get those pins clean.
Even if you are going to sonic clean it is good to use the vinegar to neutralise the electrolyte before cleaning.
The dodgy Electrolytic capacitors were conterfeit name brand caps, I have even seen OEM intel boards with these dodgy caps.
I've removed countless caps with the twist method after using hot air, iron(s), cutting, and about every other method you can think of. +1 for twisting for the win. Regarding the corrosion/salt leftover, it's probably overkill, but I sometimes just use hot air/flux to remove the offending IC, soak it in IPA while cleaning the board, and then sold back on the board. Time consuming, but leave it looking brand new in most cases. Take care!
That's exactly what I do and it's not overkill at all. That's what you're supposed to do. Leaving that salt on there does absolutely no good to the legs of chips.
i think that vinegar reacts with the electrolite (i suppose it's usually basic, like bactery residue), so it becomes neutral (aka not corrosive)
of course you have to remove all the vinegar or it's the same thing
great job mate. I also adopt similar method as you for repairs of classics. out of mixture of 7 classics and SE's, i have managed to salvage 4. did trace repair on one. the other 3 have logic boards too far corroded. i dont have any more hair to lose on those. Trace repairs can be very rewarding when you nail it but so time consuming. I enjoy your content very much. bravo brother !
I also had some motherboard issues after recapping, but with the classic II. I noticed it was inconsistent when booting up, and if I wiggled the motherboard while it was on, the screen would turn to garbage. I asked around the forums and they said it was cracked solder joints, which I thought made sense. I couldn't pin down the exact joints that were cracked, so I just ran my heat gun across the entire board. I ended up solving that problem, and my Mac could boot consistently.
Their were so many counterfeit caps back then. I have devices that are 50-70 years old and the caps are fine, but stuff from the 80's, 90's, early 2k.... I also worked in manufacturing in the late 90's and we got several batches of parts that had to be returned because they failed testing, they were name brand, but when you looked close the heat shrink labeling was different, harder to read.
51:48 Mr Burns does mac repairs. 🤣
"excellent"
What I’ve found to be very effective for removing the white salt stuff from between the legs of surface mount devices is soda blasting. I use a cheap sand blaster with a built in plastic reservoir and dump a box of baking soda in the top. It removes the residue without stripping off plating or silk screen markings.
Or just remove the old solder completely and apply new solder....
47:54 I like the way they made supports for the board as part of the case. Looks really sturdy.
I bought a used Classic II back in 1993 and I still have it. I found a retro hobbyist to recap it for me so it works again. He said it was the hardest job he ever took on. We even got the files off the old SCSI hard drive. The irony is that I had an SE for a while but sold it believing that the Classic II was an upgrade. I wish I hadn't done that now.
Classic II is faster than the base SE. IF yours was an SE/30 then I'm sorry for your loss.
I would wash the board afterwards in a dishwasher. Seriously, boards are put through a dishwasher after the wave solder process and then air dried using compressed air. This will clean up the board and the compressed air will push the water out from under the components. As always, ensure the board is completely dry before doing any work on it.
I worked in board touch-up and repair for a number of years prior to moving on to the more interesting and more satisfying testing and repair. I recommend using a burnishing pen instead of something sharp to clean the pads. That will clean the pads safely without the chance of hitting an attached etch by mistake.
Electrolytics are used for specific reasons such as better filtering and not necessarily for cost.
Have you ever thought of setting up a test setup? Take a known-good chassis and extend the power cables and cables for the CRT and connect that to an accessible power supply with cables for the motherboard. This will allow for easier testing and troubleshooting without needing to reconnecting the unit up again to test the boards. When I was a bench-tech we had setups like this for the various products and it made testing a whole lot easier.
*good* vinegar or lemon juice are essential when you are dealing with capacitor leakage, just washing the board does not neutralize the acid and it keeps eating away on the board
Hi Adrian, the vinegar is not for cleaning of electrolyte but for neutralizing it, preventing it doing more damage. The bubbling you see thats the chemical reaction you want. Its really good idea to put vinegar each time you have battery spill.
*when you have alkaline contamination
Hi Adrian, I had similar problems with memory and leaking caps on my classic. After recapping computer was alive, but memory expansion was not detected (no sad mac this time). The problem was solved by desoldering UH6 (74LS174) cleaning acid under the IC legs and soldering a new one. But another problem remained, I could no format or save to disk, and this time was the adjacent IC UI6 (74LS368) with one trace broken under it by corrosion. I bypassed this broken trace with a bit of thin cable and solved... so take a look at this IC because they are very near some of the leaking caps. And finally about the original hd, when they seem don't boot, you only need to open them and remove a little rubber black ring where head sit that gets sticky. Hope it helps, Francisco
Many of these have died via Battery leaks and capacitor corrosion. I had two. I put both away for a move, then the batteries blew and destroyed the ICs. Ate the legs of the VLSI chips.
It sucks how corrosive those batteries can be...
When we had the leaking caps issues in the early 2000s. We noticed a pattern on the top of the caps. The ones with a square cross leaked but the ones with. An offset K on top were always fine. So we were at that time in the lookout for the crappy cross caps and happy if a system had “K caps”
I've found that when you need to clean corrosion off of pads (or off of chip legs in a bad situation) , a fiberglass scratch pen does it quickly and easily. I have an A4000 which was sold to me as a known basketcase...the original owner didn't think it was savable, so I got it for a steal. I had to recap it, replace all of the clock circuitry, replace all of the simm sockets, and replace the F245 bus transceiver chip which is located right next to the clock circuit (which is also connected to on-board fast memory). All of it was corroded from a leaky battery. I've gone through a couple of those fiberglass scratch pens, and they are literal magic.
Rather than scratching the pads I've found that when using the solder braid/wick it cleans up much better if you use MG Chemicals liquid no clean flux you won't have that black residue.
Note that many/most kinds of flux _are_ corrosive to some degree, or can attract corrosive things to the motherboard. It's recommended to clean off anything except "no clean" flux, and there's no harm in cleaning that off either if you want a better appearance.
Differnet type of capacitor, especially early 90s is mostly due to capacitance available at the time, MLCC ceramic capacitor that can go into high capacitance did not exists back in the day, else that's what they would have used instead of SMD electrolytic or tantalum.
As for MLCC, the literature seems to say the opposite, the closer to rated voltage the more loss, the lower the DC voltage the less loss in capacitance (but the amount of loss will depends on the type of MLCC capacitor)
And I didn't knew that, so, I've learned something new today 😊
12:20 the electrolyte is alkaline (basic), and the vinegar is acid, so they react and produce carbon dioxide. It neutralises the gunk so it can't continue eating away at the metal, and there is less left to form salt crystals when you wash it later.
Nice MacSlap technique!!!
Tantalum caps are fantastically expensive as are solid state. At least when compared to electrolytic
Using dual iron or even tweezers I used to get a pad or two come off of every other board. Since switching to the twist method I've had no issues at all. Anecdotal but that's my experience. Also, on that analog board you'll get that fishy smell on almost every single electrolytic on there. It'll still work OK without replacing them but I definitely swapped them all out on my Classic and it runs great!
12:00. I buy cleaning vinegar for stuff like this. You can put the metal contacts from a tv remote control or kids toy into a little jar and it will neutralize the battery acid and corrosion within minutes.
17:23 , well that is more or less like limestone, same happens to washing machine, there are some products to put on the washing machine to remove the same stuff, the problem is I do not know how hard/rough will be on the board (because the washing machine inside is basically stainless steel.
I'm in the mindset that if they tend to go bad ALWAYS replace every single one even if they aren't bad.
If you're servicing a board for a customer that's a great mindset.
I've added flux to help clean pads and saved having to scrape to much, or at all
By the way! I recommend trying to use liquid instead of alcohol to clean the throttle or carburetor dampers of the car. It also perfectly cleans soldering mud with a gun flushing liquid from construction foam. However, in this case it will be necessary to be more careful with plastic products, as they can be damaged.
Also of note, ammonium perborate is itself weakly acidic, so hitting it with another acid is likely not the best idea. You need a weak base which is easily washed away, else you risk producing new acids which might cling to the underside of chips regardless of how much you wash.
The flux breaks down the oxides and avoids oxidation of the tin. It also helps the tin to wet the surface by acting as a kind of surfactant. Also There are fluxes that ain't no-clean (i guess Adrian does know very well, but young players might get into this trap). To be safe, always check the data sheet (and use a flux from a trustworthy source, if possible).
I make sure to check all electrolytic capacitors with a capacitor meter. I recommend doing this procedure with old and even new parts. Marriage, alas, also occurs. It is better to put Low esr capacitors on the power supply circuits, since they work more efficiently. In those years, these were not produced yet. Instead of surface-mounted capacitors, I put ordinary ones on my Amiga 1200, with terminals suitable in size. There is enough space and soldering is very convenient.
The vinegar reacts to the electrolyte and stops the corrosion, you don't need to scrub, just let the vinegar do it's job. It is always a good measure to use vinegar on boards that had some kind of leak from batteries, caps or even if they are rusty.
Arf, I was secretly hoping you would get a sad mac 0000000F 0000000A like I have so I could follow along to sort out my issue 😂 looking forward to see the resolve of 00000005 anyway. Never know what I could face next 😂 already excited about part 3 👍
I think it is interesting that you push the pins for the analog board fom the inside. you can get your fingernails under them from the outside and pull them up and out.
I teach life science. A couple years ago I moved into a new lab - in the cabinets I found 15 Mac’s just like this. Had the IT department take them away….. were probably barely used. Maybe a couple labs periods a year for less than 10 years…. Then abandoned in the cabinets.
By the way, you can put a mathematical coprocessor by installing it on top of the main adapter with a panel on the handkerchief, as they do on the Amiga when it is not possible to connect to the address and data bus.They actually work in parallel if you look at the scheme with a difference in a pair of signals.
Vinegar only neutralizes the corrosion. You still have to clean everything up and apply new solder to everything. You should never leave that white salty stuff on the boards, that's neutralized electrolyte and can still cause issues. You have to completely remove the old solder and apply new solder after cleaning the pins and solder pads. Otherwise you'll have loads of issues in the future.
All Mac Classics did not come with that RAM board.
To meet their under $1K price, the base model came with 1M only (no board).
That little RAM board has 1M on it and two slots. So if you see one with 2M, then it has that board.
I believe it sold with 1M (no board) or 2M (The 2M version came with a Hard Drive, the 1M didn't.). I don't recall if Apple sold a 4M version. I don't think so...
Tantalum caps have extremely low ESR and if the circuit they are in is not properly designed, inrush current will cause them to fail (and they usually fail shorted).
23:12 - My votes goes to: "bring that microscope of yours, back to the scene!"
I found that piece of equipament awesome.
The bubbling is a reaction from the vinegar with the gunk.
The powdery residue that is left behind when you cleaned the electrolyte corrosion from the caps is hydrogen. It's the same stuff that batteries produce when they rupture or if you left a light on in your car over night. Additionally I'm not sure why anyone would recommend vinegar since that is an acid. A base like baking soda or powder would be better to neutralize the electrolyte chemicals from leaking capacitors. Perhaps a combo of two would be best (neutralize with baking soda/powder then use vinegar) Certainly using IPA as you have shown many times does a good job for a final wash.
Another technique I've used for taking the clips out is to use a long thin screwdriver to push the top back out through the rivet.
Vinegar simply converts insoluble boric acid salts (electrolyte) into soluble acetic acid salts so they can be washed off. Acetic acid is not so corrosive to damage the board in 20-30 minutes.
Remember that alcohol reduces the solubility of acetates. So use water.
"On that bombshell"... sounds like a quote acquired from watching Top Gear.
We're taking a look, at the fastest Mac..... In the world!
All that board flopping around the neck of that tube was making me nervous. It’s easy to remove those couple cables and connectors and the anode is no big deal!
He said Ray Carlson maybe he meant Paul Carlson?
Yes, I have seen Paul Carlson's (Mr. Carlson's Lab) video about this. Mr. C has incredible knowledge and experience - I'd totally trust any method he demonstrates.
Yup, I think he meant Paul. He has referred to Paul a few times before, but must have accidentally misplaced his name.
I've had boards with purely Nichicon PL series caps, and the definitely DO leak just as bad.
Which is ironic because Nichicon caps of any other decade are top quality.
As usual, great video! Yes, Mr. Carlson has some great info and expert knowledge - as do you 🙂 Your Commodore 64 videos saved me sooooo much time on my last restore! I started using the wiggle method years ago to get those caps off and never had an issue with damaging traces (easy does it!). I've found that baking soda and IPA with a soft brush works great to clean up most of what you find on old circuit boards. Do you also test caps that aren't visibly leaking with an ESR meter to verify good/bad caps or do you strictly go by leaking = bad & not leaking = good? I occasionally find a bad cap that looks clean and not bulging. Looking forward to your next video!
caps,nicad and nimh batteries leak a base,so you clean it with vinegar(acid). baking soda is a base and will not neutralize cap/battery leakage.
Vinegar is useful where Varta batteries have spewed their goo. For the electrolyte problem, you might try a petroleum based solvent (e.g., WD-40) followed by an alcohol or QD contact cleaner rinse (for simple vapor degreasing).
Tip for soldering the caps on that large copper plane.... your struggling because your not waiting for it to heat the boards massive copper track, just wait till you see it start to flow then add solder as needed..
Adrian I just love how you use the wiggle method and dont give and F about what people think.
I also learned about the method a few years ago from Mr Carlson's Lab, there are other videos and sources to.
My version of it is to always push, and twist until I feel resistant then twist the other way, takes a little longer but never failed and I used it for like 2 years before I got a hot air station.
And in some cases where the cap is 1mm away from plastic connectors it might be the only way to get to it.
I remember how much flack I got on my then 300 sub YT channel when I did it the first time, its funny how a small YT gets flack, a 1000x bigger one gets applause doing the same thing!
I had people claiming to have degrees in engineering and certificates and crap claiming how I was killing the pads and people unsubed and told me how dumb I was 😆
I made it very clear in my video also not to pull but push, you want the leg to break as Adrian is saying, but yea people still accused me of pulling even after a written explanation.
Some people just cant accept some ways of doing things that they must insist reality is something else then was what shown and sad in a video.
I also had people telling me one should not solder on corrosion and yea its not ideal, there argument is that the joints will fail.
But I see pros clean up corrosion all the time with the iron or hot air like Louis Rossmann.
So if I was to listen to the wiggle haters and the "dont solder corrosion" then how the hell am I gonna get the SMD caps off? 🤣
Anyways I seen many videos where people after ripping pads, because most people will try the solder iron and lift method, this LIFTS pads, but people seems to not get that.
A pad is very strong along the axis of the PCB but it week on the Z axis so trying to lift caps is like pealing tape of the desk, bad idea.
But what I seen is then they try the wiggle method and has no issues getting old caps off.
Also a ripped pad for ANY reason can be fixed in many ways, repair kits even exist if you dont want a wire and some solder mask.
Anyways people get way to upset over how people repair there stuff, its just some caps and pads, it can be fixed.
The chemical in capacitors is apparently ammonium perborate. My first thought was that the bubbles were just CO2 like when you use vinegar on leaked batteries. But that doesn't necessarily explain what's happening here. You might be getting gaseous ammonia! I will investigate. You might also be producing small amounts of hydrochloric acid which would be BAD. If you really douse a board like this you have to wash it like crazy after.
I really enjoy your videos Adrian, I like how your always laughing in them
I turned my head away when you were cleaning the board with vinegar and thought I was listening to Bob Ross 😊
Always disconnect the flyback transformer! Never trust the bleed down resistor. Then ground the tube so the ambient charge it builds up cannot shock you.
Source: I used to work at apple and still remember those electricity cooks your veins videos from training.
Thank you for all the hard work you put into these videos. Much appreciated.
After useing a solvant with any concerning level of watter on a board i think pouring or spraying something like 90+% Isopropyl Alcohol on the board to mix with remaing watter wich should borh dilute the watter and evaperat the watter much quicker sence IPA evaporates quick.
After i have used vinegar and wash with soap, i let it air dry and after that give them a good bath of ipa. Seems to work.
I don't think I would be comfortable placing a motherboard in an ultrasonic cleaner. I would be too afraid of the vibration damaging the bond wires inside the IC chips. Bil Herd did a fantastic talk about component aging and failure, and he mentioned vibrations and failures.
Regarding the Mac LC, while considerations regarding market segments would have probably been a thing, there is also a real reason behind this market segmentation: 16-bit boards and their various components were just cheaper, helping with the low price point.
(Compare the i8088, used for the same reasons in the 16-bit era, since 8-bit boards were significantly cheaper, or the original Mac board vs. the Lisa. Consumer computers were never about what could be made at the state of art, but what could be made to a certain price point. It may be more than a coincidence that "computer" is spelled with a "c" as in "compromised"…)
20:42 krusty crab? Mr Krab likes you named his restaurant.
Thank for good Learning first i had try to find the treasusre ready.The name of this Console is Phillips G 7000
great info for us old school
Glacial acetic acid is free of process derivatives, aka sugars and pulp. Its generally not a big deal if you buy the heinz white vinegar, but some may prefer it.
Hey Adrian! I cleaned the white thing on the board components' legs with IPA 99% on a q-tip.
I just got some guts and wiggle-method removed all the caps from my mac classic board. I had been waiting for years but was too afraid! No longer! Just ordered some tantalums. I suppose I will have to look at the psu, too.
the vinegar is supposed to sit and the bubbling is the reaction of it eating away the corrosion.
Tantalum caps are sometimes expensive, yes. I replaced all the ones on my IBM PC/XT/AT series, and the cards within. Some of them were STUPID expensive for their size. Over a buck apiece for 22uF? C'mon.... So yeah, that's probably why electrolytic were more common.
Consider using/buying an ESR meter to test the caps. They even work in circuit and are a must have tool for troubleshooting and general maintenance. It can detect failing caps before they leak or bulge
He has one
Ultrasonic cleaning is the way to get rid of the brown stuff, and it cleans under the chips etc. Not cheap but it will get everything off.
If I remember, the problem with 90's capacitors is due to corporate espionage gone bad. If I remember the news at the time, some Chinese manufacturer stole the electrolyte formula from a major manufacturer, but they botched the recipe, so capacitors manufactured with that formula all leak and fail over time.
Unfortunately, before the news broke and everybody found out, they sold millions of capacitors as counterfeits of all the major brands, and manufacturers everywhere bought them, thinking they were getting good quality and discount prices. And we're still suffering the aftermath of that mess today.
Adrian, we all know you're in the pocket of Big Capacitor. That's the real reason for the wiggle/twist.
Yesterday I recapped my Macintosh Classic with fresh tantalums and my process wasn't too different from what you showed here. In my case though, one of the vias in-between the central caps has been completely eaten away by the corrosion, so I had to solder a wire onto the nearby trace and onto the remaining pad on the other side of the board to restore continuity. Fortunately that did the trick and the Mac Classic is now working perfectly again.
I will have to take a look at the analog board sooner or later. Right now there doesn't seem to be any sign of leaking or corrosion, but I can't quite make out the series of Nichicon caps that are on there, so it's a bit too early to celebrate I think. Good to know what to look out for, in any case. That reminds me, did you happen to take note of the markings on the board next to the six capacitors that you removed? The console5 tech wiki lists all of the various capacitor types on the analog board, but I don't know exactly which ones are the brown Nichicon caps.
I'm not sure if the black gunk youre seeing is coming from the caps. It looks like the rosin flux that's in the center of the solder and also used in the solder braid. I get that a lot at work. Usually just IPA and some cotton swabs and it cleans right up
Vinegar is mostly to neutralize any alcaline solution. I works on the iquid of some caps and batteries, but mostly to prevent further corrosion by turning the alkali into a salt.
To eliminate the salt residue, you need to know what exactly goes into those caps/batteries and, after neutralizing the spillage (you may need to use a different reagent, like ammonia, depending on the specific leaky component), use the correct solvent (e.g. water, alcohol, acetone, a table salt solution, a coppersulphate solution, a rust remover, etc.)
Abit had the big case with leaky caps, one of the things what make it go down..........
In my experience, vinegar works really really well with battery electrolyte. Alkaline goo is especially good to use vinegar on. It’s stunningly effective, I use it all the time when restoring old toys.
Glancing through some literature, caps can be acidic or basic or neutral, so a bicarbonate solution may also be good. You’ll want to throughly rinse between the vinegar and bicarbonate though.
Interesting.
Nichicon SXE are early Low ESR types.
Maybe that's why they leak?
Seems to be the case that the lower the ESR the worse the caps...