Chips of widely differing years are typically indicative of a closing plant. The order will come down to end production - that does NOT mean they stop assembly. It means that the company will assess exactly what parts they happen to have on hand from all previous products. They then plan on how many final products can be made from available parts. Production will continue from miscellaneous parts. The decision to end production may be made early, but if a single part can help produce profit, it will be ordered "post-production" -- IF the part can be used in a future product. Basically, they run out the line, depleting existing stock as much as possible, buying new parts IF they can be used for future products as well. When a product is either scaling up or is in full scale manufacture, new parts are on order constantly. Some companies use their old parts, others don't. We often talk about Commodore computers where old parts being used on a board is very uncommon. That's largely because Commodore would redesign the board making many old chips unusable or at the very least undesirable. Other manufacturers made boards that also used custom chips that only they could produce as well. Manufacturers that went with more generic parts used "off the shelf" parts that get used on multiple products. This can lead to an accumulation of parts from a wider range of years - but the earlier chips won't get used initially. They'll sit on shelf somewhere else until a product is terminated and then a call goes out for parts on hand. Those parts will then be added to others and those will be used to finish production of what's left. All of the parts have already been expensed. The remaining costs for labor, utilities, etc. will be all used to price the item. It will likely be sold at just over cost for a marginal profit. Lots of shady retailers resell out of date equipment to unsuspecting individuals or even businesses. Sometimes the equipment is donated as a charitable item and this is a tax write off.
My Dad got an Apple II+ in the early 80s and used it to learn BASIC programming as he switched careers shortly before I was born. This was our family computer into the early 90s and got me hooked on computers growing up. Seeing you meticulously cleaning and caring for this computer warmed my heart. My Dad is 70 now and still has his Apple II+ in working condition. Thank you for making this video. 💛
As for the color bars, when I was little, I always had a fascination for watching color bars on TV that one of my local channels had back in the day at 5:30AM before the channel would begin its broadcast day. Those color bars had a section in the middle that had the broadcast channel number and call letters in white letters. As for electronics, I loved taking them apart to see what made them work, and even put them back together.
One of the first things I do with old socketed boards is to re-seat the IC’s. You can usually hear the oxidation cracking as you ease out the chips! In many cases I find this alone will revive a dead board. When you were cleaning the board, I was thinking that I would’ve removed all the chips from their sockets first. :)
That's a usual Adrian thing. Test first, then reseat and deoxit the chips. Here, the chips seem to be getting voltage in spec with the power supply, so probably a good thing for the next video.
@@chemmerling Yes, I suspect you are correct. With old boards I generally start with just a cursory clean (eg. compressed air and brush), before an initial test power-up. When that fails, simply reseating all socketed IC's and connectors is then my next step, which in many cases gets me a working outcome (which I then follow with a deep clean).
Hooray! Someone else that scrubs their circuitboards in the sink. People get so upset about this, but it's the best way of cleaning a circuitboard (though not a PSU/CRT circuit etc...). I've done this so many times and it makes a huge difference. In the UK quite a few homes have an airing cupboard (where the hot water tank is), and I leave the cleaned board in there for a week. Also, for cleaning grime and really mucky stuff, test a small patch with Isopropyl 70% alcohol - amazing at getting rid of grime, and really good on casings.
My first computer was an Apple //e back in 1983. It still works. More recently I was able to purchase a gadget that lets me connect a Disk ][ to my Mac via USB. :)
Last used real hardware back in 2016 or 2017 (I forget which Geek Group trip that was), only messed around with BASIC and couldn't save as the disk drives weren't hooked up and neither was a cassette recorder.
Back in the 70's I used to hang out at a computer store on my way home from school. Somebody brought in an old S-100 bus computer that didn't work and one of the memory cards had something spilled on it. Although I think it was only an 8K card, the chip density was unbelievable. The guy who ran the store stuck the board in a dishwasher and dried it, and it worked! I've done similar things to electronics in my career. Once you've dumped a soda in your device, a little water is likely not going to make it worse. The Korg Polysix with the cat pee on the digital board was the worst.
Dirty but not as bad the the spider farm that was going on inside a Sony PVM that Retro Tech restored recently. I love the cleaning montages, especially keyboard keys, so satisfying.
One common issue with Apple II Plus is the chips creep out of the sockets from heating/cooling cycles. This is especially bad with machines fully loaded with cards... I have fixed many back in the day by simply pushing all the chips down into their sockets!
Actually my Apple II Plus got so bad that it would overheat within about 20 min of turning it on and would start to "glitch", but then again, I had it filled with cards! My teenage solution at the time was to mount a 120Vac muffin fan (from Princess Auto!) inside the case so it would blow air across the motherboard... I cringe to think that I actually drilled vent holes into the plastic at the side where the fan was mounted (close to the joystick port), but it worked a charm and never overheated again! Of course, the computer was a little noisy though... :)
Adrian, there is a small white silkscreened square on the motherboard near the power connector - this is where Apple stamps the date code for the entire motherboard completion. Hopefully the stamps is still visible after the thorough cleaning you gave it! Also note that the square is a little small for the stamp, so it is common to have a number to the left or right of it on the green (extra-hard to see!!)
@@Johnny-es9xg But he should, after all the stuff he has fixed, known better not to do those boneheaded fixes. I did not say anything about that until now but it was rather bone headed even for Dave.
@@Walczyk Mostly the dremmel on the edge of the screw really. He should have just waited and gotten the keyed star OR at very least, dremmel across the screw head and use a flat to take it out. You can get those keyed drivers anywhere nowadays and he went to the store. The paper clip does not bother me except for the fact that he should have done some more thorough continuity tests before trying it. 8 bit guy is a great channel and I watch it all the time and usually he is very thorough about how he goes about repairs. However, when you have something as apparently as rare as that machine seems to be, you certainly want to take better caution. Dave could be right about it being a proto that never really worked properly in the first place but to me that is just more the reason why you want to take whatever extra steps and be much more careful than it seemed he was being. I'm certainly not upset at him or will disown him as a result of it like some people did ...we've all been boneheaded at times but in a rare case like that, I think erring on the side of caution is always best.
deamondeathstone1 good eye!! Yeah, looks like 33rd week of 1982, but weird that it seems to be WWYY instead of YYWW as I have always seen... So any chip past that date must have been replaced! (Looks like two - 25:25 we see 8311 and 8246)
Ah, the look of a bygone era... where PCBs had through-hole components with silk-screened part #s for easy servicing. None of the surface-mount rubbish! 😊
Note the other comment about date codes - your motherboard has a stamped date code of 3382 (weird! It is usually YYWW, but let's assume someone was mixed up!), so 33rd week of 1982... I see from your list that you have two chips from past that, so these must have for sure been changed. Also, I think you are right to suspect those 3 mismatched early chips as well! My 7935 Apple II Plus has different RAM brands for each 16K bank, leading me to believe it was first assembled as a 16 KB motherboard and then expanded on two separate occasions (perhaps even before it left the factory, since I think they standardized on 48KB by the time the Plus came out!)...
Repair hints as I remember from Dr Levinson... You can remove the BASIC ROMs ($D000 - $EFFF); leaving the 2 $Fxxx ROMs. This will give the "Apple ][" and break into Machine Language Monitor. Look at the language card, as the RAM chip from the mother board is moved there. Take it out and put it on the mother board. That will give you 48k. Press all the chips on the socket, no doubt water got between the chip and the socket. The rest you know from fixing C64s. Check the clock and the reset lines. Check the video connector. Etc... Edit: I forget- check the video cable too.
The timing of this video series couldn't be better. Pulled out my childhood ii+ a couple weeks ago to go through. Also, I ordered up my first bottle of 303 while watching this video;)
David Perkins gave a great suggestion. There's a good reason that mainstream manufacturers quit using socketed chips long ago. Each one of those contacts is subject to invisible corrosion. (OK - sometimes it IS visible!). Use a chip puller or a small screwdriver to partially remove and reseat every chip a few times. It's too much trouble to pull them completely out, plus it's easy to get clumsy and bend pins when pushing an IC back in. Not guaranteed to make your old clunker work again, but well worth the fifteen minutes it takes to do. Back when sockets were common, badly trained industrial techs would remove a chip, replace it with a new one, and repeat until the board under test worked or they swapped every one of them without finding the problem. (Then they had to start thinking instead of acting like a dumb chimp, but that's a different story. ) Anyway, often enough that worked. The problem was that they did this with boards powered on throughout. This was when 4XXX CMOS chips were common, so while they usually got by with it, there was a good chance that they caused damage that wouldn't fail completely until later. The point of this is: Don't ever remove a chip without making sure power is off and using a wrist strap. Lots of people get by with ignoring this, but in the long run it's a bad bet to make.
You might want to spray the rusted broken screws in the case with WD-40 and let that soak in for a while before trying the dremmel trick on it next time.
@@infinitecanadian True, though they got the resolution in exchange. I lived through the late 80s and early 90s making the joke that we recorded everything on masking tape! 😂
While true, NTSC allowed WOZ's color hack to work allowing us to have color as early as the Apple II. PAL regions didn't get it on composite or if they did it would have only been on the IIgs or an adapter for the //c.
A thought for the cloudy plastic on the keys, I've used a metal polish called Peek when I've had dull or lightly scratched plastics, and it polishes out the cloudy dullness nicely, usually that's oxidation of the plastic when it's that light powdery look, which polishing removes and smooths things out nicely... :)
Eek!! I would have done a chip reseating and got it working before a deep clean like that, and only done a dust removal (vacuum) first and a recheck. Also with those power supplies, you need to be really careful. Some of the rails are only managed with zeners and if they blow, you can take out a board (or at least a few chips). A single dry cap can throw all the rails off. Best to test against a test load block before applying it to a board. where I worked, we had a lab of apples + clones. The clone supplies were actually more reliable than the apple ones, those of which were often replaced by a clone supply for safety. The most common failures were the ram chips which always ran hotter than the rest so that was the first port of call. Best of luck!! looking forward to the next clip to see if it survived ;)
Dude! Goo Gone makes a great key cleaner. I let them soak in it overnight then rinse them under a small stream of running water. The dirt and grime practically fall off! Afterwards, I filter the Goo Gone and set it aside for re-use on the next project.
9:08 - I've tried a lot of over the counter products for cleaning plastics and really like Meguiar's G4116 Natural Shine Protectant ($5 in the car cleaning dept @ Walmart) applied with a micofiber cloth. Gently cleans without damaging/drying out the plastic and gives the surface that perfect satiny just-out-of-the-box look, especially on textured materials. Works great on car interiors too, of course.
For broken screws and bolts, a left handed drill can help if needed, if it grabs the screw in reverse it will tend to unscrew it, if not, it will drill it out. Just be sure the drill is well centered.
At the 6:55 mark you are correct about the Apple //e keyboard. The logic is all on the motherboard. If I recall correctly you can actually simulate key presses to some degree by unplugging the keyboard and jumpering the pins around.
I have an Apple 2e, Color monitor, and floppies that were in a threshing barn for at least 20 years. The 2e was not too bad but did have a fair amount of seed, husk, dirt/dust, and bugs. The floppies were really bad-off with dirt, mouse poop, urine, seed, husk bugs, and other unidentifiable's. I found 4 drives and made two workable. I did tear the 2e down and cleaned it good. There was also a C128, 1571, and Excelerator Plus. The 128 needed a good bit of cleaning, as it was near the thresher but the drives were near the apple 2e. That keyboard you had was clean compared to the 128's. They were loaded with years of crap! The 128 was spider central and it had so many bugs in it (hence the spiders). I took a lot of time with it and it still has some KB issues but now looks good for its living location. I had to reflow the power jack and switch, flush and clean (many times) the power switch. I never knew so much stuff could be in such a small space! The KB needed a few plungers 3d printed (I used tinkercad to make) I had to recoat the KB traces as they there shot in places even before cleaning. I just used an old #2 pencil and colored happily for over an hour. The PSU was dead as well and I used a 9VAC wall wort and a Hi-Link HLK-20M05 for the 5V and placed those back in the PSU case. I plan to recap it all at some point soon as well, but surprisingly they all seem ok but will do them.
@Adrian's Digital Basement The splotching is due to the oxidization breakdown of the plastic. The trick I used years back is a sealant for plastic car parts. Make sure its a nonreactive sealant.
I used to work at an authorized apple educational repair center, we shut down the old apple repair service when apple shut down the program. We had tons of factory new inventory parts for Macs and Apple ]['s, Most of it went into the dumpster. I wish I would've kept it all, the owner probably would've said, take it if you want it.
VERY lucky to have an Alps keyboard Adrian! The Datanetics keyboards … replacement switches are hen's teeth. Datanetics is definitely more desirable among collectors, but Alps is more desirable if you want to be able to fix it. Me? I'm kind of in the modern Cherry-style replacement camp, if only because I'm interested in having options that don't involve finding dead machines to pick over for parts (or rather, the actual fear, machines that worked that were parted out and destroyed by unscrupulous eBay sellers). Not only that, I'm starting to be interested in modern cost-reduced clones of the old machines. I think the biggest impediment before was that starting in about 1980 the machines started getting not only rapidly more complex, but also rapidly more based around custom chips that you just can't get anymore. It's bad enough there are so many standard chips you can't get anymore. But these days the tools to make them are becoming affordable and available to hobbyists. So now's the time to recreate these things if we want them! (And we do!)
Try a pair of vise grips if there's part of the screw shank still sticking out from the hole. Gotta be careful not to apply too much torque, of course. Outstanding channel and videos BTW! Thanks so much!
The manufacture date of the II+ main board is on the white square on the corner of the motherboard by the power connector. It's handwritten on one of mine ("8139") and stamped on my other one ("2182"). At 1:48, you can see that yours is stamped with "3382". While I didn't check each and every IC, my 1982 board probably has a few more 1982 chips than 1981 chips and I also saw an 1980 date code. Maybe someone found a couple of old parts bins the week that your board was stuffed.
Older TVs, I'm talking up through the 1980s at least, had a dedicated circuit called a "color killer", which turned off the color circuits when a monochrome signal was being broadcast, improving the monochrome picture quality and eliminating any spurious color in the monochrome picture caused by interference. TVs of that era didn't have too fancy of filters to disable. I know this is a monitor, so a bit different.
Years ago (2007-ish) I picked up an entire school computer lab of everything from II Plus to IIe Platinum that failed to sell at a yardsale in Tennessee. The early 80s systems had a mixture of old/new chips, while toward the IIe Platinum it was mostly a newer / consolidated design. I don't know when they started consolidation, but if had to guess, 82 or 83. I had a bunch of expansion cards including some test readers that were used by the school.
I am so surprised to see you pointing out that 8T97. I just had to go see and yes I still have many of them dated 7912 and 7948 and also some other 8T series. Didn't really have any info on them back then when they were given to me as a kid to play with so I was curious about them for quite some time. Ah well, if you ever need one of those I can get you one :D
The keyboard encoder was an AY-5-3600 by General Instruments which was a purpose designed PMOS device that used a couple of ring counters, a comparator, and a 3600 bit ROM to scan for switch closures and generate keycodes. As a side note however... by 1983 GI was selling the KB3600-PRO which was a PIC1650A microcontroller with a mask ROM for emulating the AY-5-3600 while adding a couple features. Those 8T97s are the address bus buffers and blew occasionally when other address logic went up so I'm not surprised on the different chips. In the factory, all three were parts from the same feeder.
Great videos series, thanks for sharing-I'm the original apple II kid, but personally I wouldn't have cleaned it before finishing the trouble-shooting since from my experience, it's too easy to introduce another issue thereby compounding the repair process. Your initial smoke test symptoms: power light on, screen filled with gibberish, no beep, indicates bad MOBO or PS. Since you tested the PS, the next thing I'd check is the 74LS74 power reset chip, then the crystal, or one of the 8T97 chips.
I remember the first time I tore a keyboard apart to repair I did not think to map out where each key went so I had to use my type by touch to remember where each key went. Basically remembering what each key I hit with each finger. That only happened to me once.
I've had good luck removing seized, broken-off screws with a left handed drill bit, for what it's worth. Harbor Freight sells a set inexpensively, and for how infrequently I use them (like, 1-2 times a year?), they've been fine.
The marks on the side of the keys is normally due to grout from fingers. The mix of dead cells, sweat and dirt act as an acid and discolour the plastic! As for a dirty machine - long way to go. I had machines returned to IT where you could not see the chips on the board from the dust and bits - yuk. Worse keyboard was one from a home office set-up where their youngster had an 'accident' without nappy (diaper) and they returned it to the office for us to clean - yuk yuk yuk.
Always learning so much, thanks a lot Adrian ;) Btw some day you should do a video on how you setup your basement, with the tables and how you are evolving down there ;) would love to know more about that.
@@Kedvespatikus I didn't mean it was specifically developed to loosen screws... but more of getting down into rusted areas to un-cease and lubricate, and such..
Kroil might be a better choice, but if it the bolt was already rusty and someone used excessive speed/force putting it in there may be no removing it. After trying a few things, it might be easier to drill out. There are bits for extracting bolts and remaking the threading. Not particularly expensive either.
@@Ghozer WD-40, short for "Water Displacement Formula 40" was developed for application on rockets to protect them from corrosion by Rocket Chemical Company, later renamed WD-40 Company. It was only much later discovered that WD-40 had also a much wider variaty of use cases, so they began to market it first towards businesses like airlines and general industry and later also the common consumer. WD-40 isnt a lubricant, its sole purpose is to keep water from a surface that it was applied to for the short term.
they added a beefier spring inside the reset key in your model as well. I remember the reset key frustrating me when I was a kid in school cause it would reset out of the game as well
As I commented before on the last board you washed, never use tap water from the faucet. Tap water has too many things into it that will ruin a board. Back then you stated that your water is filtered but that is not the issue. The issue is others copying what you do and then ruining their boards because their water is not filtered. (My NYC tap water will leave a board wrecking white residue if I dare wash a board in NYC tap water! ) If you must wash a board use and demonstrate using distilled water from a jug. Thank you.
I totally agree with you. His lack of ESD precautions makes me wince too when he is handling components, considering how old machines like that Apple getting rarer and rarer you would think people who have them would take every possible care in when handing chips and motherboards.
Sharpness is increasing or decreasing the highest frequencies of the video. As an analogy, in the audio realm, it's like a treble control. Jump the frequency up a couple megahertz,. and you have a sharpness control. The highest frequencies of the video signal contain the detail information. Boosting it too high can cause "sparkling". Decreasing the sharpness, removes some of the detail. The key to sharpness is to get the best signal without sparkling.
I love the monitor. Pitty the clean up of the motherboard made it worse. It's amazing how often that happens. For the past 6-7 years, if I plug something in and it works then I don't mess with it. LOL. :) Looking forward to the next part.
alot of people believe Apple only puts 'Premium stuff' into their computers, but that is not the case at ALL! This is very normal for Apple II's. All of the Apple II's I repaired had a crazy mix of chips.
What a great video! Adrian, have you thought of doing a video on "monitor basics" both for color and monochrome displays? You have such a deep level of understanding of these concepts, and it would be fascinating to learn more! :) Keep up the amazing work!
To add to Greg Gall’s comment, the PC board manufacturer usually adds a date code at the copper level, (if not, sometimes as part of the silkscreen level), usually in YYWW or WWYY format.
That is so scary to see you washing motherboards with soapy water 😅. I know that you know what you are doing but I never ever dare to do that by myself. Great video once again.
My open bench liquid cooled VR PC started leaking during a beatsaber session one day so I just washed the motherboard and GPU in hot soapy water and dried them, still works great. Also revived a lot of spill damaged laptops at my old job with the same method.
Don't know if you have this stuff up there, but Nifti is stronger than Windex. Next stronger is a good brand Sugar Soap. These ammonia based cleaners don't need much if any scrubbing. You could also try bleach. Plastic can be polished like any car paint so for the key sides you could use 2nd cut and polish, which is slightly abrasive to clean and smooth, and polish to make it glossy. Cutting compound first if it's really bad. CLR eats rust, so it might have got the rust out of the broken screws threads so they can be unscrewed. Vinegar is milder, but might also work.
Also, in my experience working in an electronics manufacturer, it’s not uncommon to have multiple vendors for a given part, so some of the vendors likely had various lots of a given part, especially if they were a second-string vendor (buying up leftover lots from the manufacturers when certain products get discontinued etc.). As a case in point, one board my company built up until the mid 2010s had a fairly scarce IC, and the lot that was located to allow us to keep building as long as required had a 1981 date code! So, the variation in date codes would be somewhat reasonable for a vintage 1983 Apple.
Hey Adrian, some chip manufacturers stamp some info like date codes and type also on the underside of the ic package. I lately found that on some fake AY-3-8910 that had suspiciously new looking topsides on the underside still had original date code and YM2149 stamps on. So check the underside to see if this can clear things up.
Hey Adrian, nice videos. I think you have previously said you come from a professional IT background. If that's hardware v software then you would have had ESD precautions drummed into you like the rest of us have for the past 40 years. It would be great to see less comfy rubber mats and more ESD precautions on these treasures. Cheers.
13:33 Newer Apple II plus models had a switch at the top of the keyboard just inside the case. When activated you had to press control with the reset button.
Adrian, a date code span of 12-15 months wasn't unusual in the Apple II+. This was due to variations in the supply chain, where some of the chips were available in large lots (and thus an older chip might make its way into a newer unit) and other chips were available in smaller lots. However, the 5-year span of date codes in this example is suspicious. The keyboard and encoder, and the layout of the motherboard, make it clear this is a late II+, probably a Rev. 7 board, so that 1978 chip is way out of place. Perhaps this was used as a donor machine to keep another II+ working, and the "bad" chips were put back into the donor machine to be "tested again later" --- without marking them, of course. A terrible practice, yet one I have encountered before. It will be very tedious, but since the II+ has mostly standard TTL chips in sockets, I encourage you to simply test every TTL chip to determine if they are good. This will also create the opportunity to reseat all of the chips. Don't assume the first bad one you find is the end of the story. Until you have verified everything, treat it more like a bag of loose chips than a complete computer. As others have pointed out, you can also try booting after removing all but the Fxxx ROMs, you can remove all but the first 16K of RAM, and you could swap in another 6502 processor from your stock (or a Commodore disk drive).
For removing screws, you might want to get a set of screw extractors or EZ-Outs. They are a little like taps, but left-handed and wedge in the hole you drill. There are left handed drill bits that sometimes will spin out a screw on their own, too.
I think you need to populate the missing DRAM IC. The chip is normally removed and put on the memory extension card. This trick allows the extension card to gain access to DRAM timing without having to add additional logic. Or put the language card back in. Just my guess though as I have never serviced them before. Unless you count hitting them with the _Fonzie fist_ to get them to boot (due to bad socket connections on the mainboard, did that lots on the high school Apples, in the before times.) Cheers,
stuff carried over from telegraph machines the G key says BELL on it. They press a ctrl or like an alt key on the telegraph machine to ring a bell on the machine you are sending to. maybe tell them a message is coming through or ending of a message etc.
I would think that if it was worked on, the repair shop may have used either what chips they had in stock, or what ones they could harvest from dead systems. That would explain the wide range of much older chips.
You sure you always have the 'Notify subscribers' checkbox enabled when uploading videos? Only cos I don't hear _anyone_ else complaining as much about the YT notifications... In fact, it's one of the only things I hardly ever hear anyone complaining about where UA-cam's concerned... Also, I do receive your notifications most of the time, so I figure this little checkbox I'm referring to is enabled the majority of times. So... That's a thing... Apart from this, I really liked this vid!
I prefer using citric acid with few drops of dish soap instead of vinegar. It takes the rust off better and is less damaging to healthy metal. @10:45 When you were cleaning the keys. Was this shango066 repair video that you were watching?
You should probably put up a trigger warning when using a dremel. The mental scars haven't fully healed for a lot of people who witnessed that IBM prototype getting butchered by one.
Chips of widely differing years are typically indicative of a closing plant. The order will come down to end production - that does NOT mean they stop assembly. It means that the company will assess exactly what parts they happen to have on hand from all previous products. They then plan on how many final products can be made from available parts. Production will continue from miscellaneous parts. The decision to end production may be made early, but if a single part can help produce profit, it will be ordered "post-production" -- IF the part can be used in a future product.
Basically, they run out the line, depleting existing stock as much as possible, buying new parts IF they can be used for future products as well.
When a product is either scaling up or is in full scale manufacture, new parts are on order constantly. Some companies use their old parts, others don't. We often talk about Commodore computers where old parts being used on a board is very uncommon. That's largely because Commodore would redesign the board making many old chips unusable or at the very least undesirable. Other manufacturers made boards that also used custom chips that only they could produce as well. Manufacturers that went with more generic parts used "off the shelf" parts that get used on multiple products. This can lead to an accumulation of parts from a wider range of years - but the earlier chips won't get used initially. They'll sit on shelf somewhere else until a product is terminated and then a call goes out for parts on hand. Those parts will then be added to others and those will be used to finish production of what's left. All of the parts have already been expensed. The remaining costs for labor, utilities, etc. will be all used to price the item. It will likely be sold at just over cost for a marginal profit. Lots of shady retailers resell out of date equipment to unsuspecting individuals or even businesses. Sometimes the equipment is donated as a charitable item and this is a tax write off.
My Dad got an Apple II+ in the early 80s and used it to learn BASIC programming as he switched careers shortly before I was born. This was our family computer into the early 90s and got me hooked on computers growing up. Seeing you meticulously cleaning and caring for this computer warmed my heart. My Dad is 70 now and still has his Apple II+ in working condition. Thank you for making this video. 💛
As for the color bars, when I was little, I always had a fascination for watching color bars on TV that one of my local channels had back in the day at 5:30AM before the channel would begin its broadcast day. Those color bars had a section in the middle that had the broadcast channel number and call letters in white letters.
As for electronics, I loved taking them apart to see what made them work, and even put them back together.
One of the first things I do with old socketed boards is to re-seat the IC’s. You can usually hear the oxidation cracking as you ease out the chips! In many cases I find this alone will revive a dead board. When you were cleaning the board, I was thinking that I would’ve removed all the chips from their sockets first. :)
I thought about that as well, but there is a significant possibility of introducing a problem that wasn't there in the process. That is a lot of ICs.
That's a usual Adrian thing. Test first, then reseat and deoxit the chips. Here, the chips seem to be getting voltage in spec with the power supply, so probably a good thing for the next video.
@@chemmerling Yes, I suspect you are correct. With old boards I generally start with just a cursory clean (eg. compressed air and brush), before an initial test power-up. When that fails, simply reseating all socketed IC's and connectors is then my next step, which in many cases gets me a working outcome (which I then follow with a deep clean).
Hooray! Someone else that scrubs their circuitboards in the sink. People get so upset about this, but it's the best way of cleaning a circuitboard (though not a PSU/CRT circuit etc...). I've done this so many times and it makes a huge difference. In the UK quite a few homes have an airing cupboard (where the hot water tank is), and I leave the cleaned board in there for a week. Also, for cleaning grime and really mucky stuff, test a small patch with Isopropyl 70% alcohol - amazing at getting rid of grime, and really good on casings.
It's dirty, but at least it didn't have a living ant colony.
You mean "Anthill Inside"?
@@MoseyingFan Yeah, like the fieldfound C64.
Likely there are hopefully no coronaviruses there inside the apple 2 as they may keep watching on us, o,o,o.
@Brandon Taylor 'Zero Wing' much? :-)
@Brandon Taylor I know. I was making a reference to the iconic game quote from Zero Wing: 'All your base are belong to us'. Just a joke :-)
I last used an Apple IIe back at school, some 37 years ago.......thanks for the memories!
We still had 2 or 3 Apple IIe's in 1990, my first grade classroom. I used to play Oregon Trail whenever possible.
My first computer was an Apple //e back in 1983. It still works. More recently I was able to purchase a gadget that lets me connect a Disk ][ to my Mac via USB. :)
Last used real hardware back in 2016 or 2017 (I forget which Geek Group trip that was), only messed around with BASIC and couldn't save as the disk drives weren't hooked up and neither was a cassette recorder.
Back in the 70's I used to hang out at a computer store on my way home from school. Somebody brought in an old S-100 bus computer that didn't work and one of the memory cards had something spilled on it. Although I think it was only an 8K card, the chip density was unbelievable. The guy who ran the store stuck the board in a dishwasher and dried it, and it worked! I've done similar things to electronics in my career. Once you've dumped a soda in your device, a little water is likely not going to make it worse. The Korg Polysix with the cat pee on the digital board was the worst.
When I used to write business software for the Apple II+ we put a rubber washer under the Reset key to prevent accidentally resetting. ;)
Dirty but not as bad the the spider farm that was going on inside a Sony PVM that Retro Tech restored recently. I love the cleaning montages, especially keyboard keys, so satisfying.
There is something odly satisfing to see things get a good cleaning and ending up looking nearly like new.
One common issue with Apple II Plus is the chips creep out of the sockets from heating/cooling cycles. This is especially bad with machines fully loaded with cards... I have fixed many back in the day by simply pushing all the chips down into their sockets!
I thought that was more of an Apple /// thing.
@@GaryCameron780 - Nope Apple II as well. Had to do that all the time back in my high school days.
Actually my Apple II Plus got so bad that it would overheat within about 20 min of turning it on and would start to "glitch", but then again, I had it filled with cards! My teenage solution at the time was to mount a 120Vac muffin fan (from Princess Auto!) inside the case so it would blow air across the motherboard... I cringe to think that I actually drilled vent holes into the plastic at the side where the fan was mounted (close to the joystick port), but it worked a charm and never overheated again! Of course, the computer was a little noisy though... :)
Had the same issue with the floppy drive ROM on my C128D so it is prudent to check chip seating.
Adrian, there is a small white silkscreened square on the motherboard near the power connector - this is where Apple stamps the date code for the entire motherboard completion. Hopefully the stamps is still visible after the thorough cleaning you gave it!
Also note that the square is a little small for the stamp, so it is common to have a number to the left or right of it on the green (extra-hard to see!!)
@@Johnny-es9xg But he should, after all the stuff he has fixed, known better not to do those boneheaded fixes. I did not say anything about that until now but it was rather bone headed even for Dave.
@@GORF_EMPIRE which one?
@@Walczyk Mostly the dremmel on the edge of the screw really. He should have just waited and gotten the keyed star OR at very least, dremmel across the screw head and use a flat to take it out. You can get those keyed drivers anywhere nowadays and he went to the store. The paper clip does not bother me except for the fact that he should have done some more thorough continuity tests before trying it. 8 bit guy is a great channel and I watch it all the time and usually he is very thorough about how he goes about repairs. However, when you have something as apparently as rare as that machine seems to be, you certainly want to take better caution. Dave could be right about it being a proto that never really worked properly in the first place but to me that is just more the reason why you want to take whatever extra steps and be much more careful than it seemed he was being. I'm certainly not upset at him or will disown him as a result of it like some people did ...we've all been boneheaded at times but in a rare case like that, I think erring on the side of caution is always best.
So 3382 as seen around 3:58 ?
deamondeathstone1 good eye!!
Yeah, looks like 33rd week of 1982, but weird that it seems to be WWYY instead of YYWW as I have always seen...
So any chip past that date must have been replaced! (Looks like two - 25:25 we see 8311 and 8246)
Ah, the look of a bygone era... where PCBs had through-hole components with silk-screened part #s for easy servicing. None of the surface-mount rubbish! 😊
I recall there being quite mix of date codes on the IC’s in my original Apple II Plus from years ago, so yours may not have been messed with much...
Note the other comment about date codes - your motherboard has a stamped date code of 3382 (weird! It is usually YYWW, but let's assume someone was mixed up!), so 33rd week of 1982... I see from your list that you have two chips from past that, so these must have for sure been changed. Also, I think you are right to suspect those 3 mismatched early chips as well!
My 7935 Apple II Plus has different RAM brands for each 16K bank, leading me to believe it was first assembled as a 16 KB motherboard and then expanded on two separate occasions (perhaps even before it left the factory, since I think they standardized on 48KB by the time the Plus came out!)...
Repair hints as I remember from Dr Levinson...
You can remove the BASIC ROMs ($D000 - $EFFF); leaving the 2 $Fxxx ROMs. This will give the "Apple ][" and break into Machine Language Monitor.
Look at the language card, as the RAM chip from the mother board is moved there. Take it out and put it on the mother board. That will give you 48k.
Press all the chips on the socket, no doubt water got between the chip and the socket.
The rest you know from fixing C64s. Check the clock and the reset lines. Check the video connector. Etc...
Edit: I forget- check the video cable too.
The timing of this video series couldn't be better. Pulled out my childhood ii+ a couple weeks ago to go through. Also, I ordered up my first bottle of 303 while watching this video;)
David Perkins gave a great suggestion. There's a good reason that mainstream manufacturers quit using socketed chips long ago. Each one of those contacts is subject to invisible corrosion. (OK - sometimes it IS visible!). Use a chip puller or a small screwdriver to partially remove and reseat every chip a few times. It's too much trouble to pull them completely out, plus it's easy to get clumsy and bend pins when pushing an IC back in. Not guaranteed to make your old clunker work again, but well worth the fifteen minutes it takes to do.
Back when sockets were common, badly trained industrial techs would remove a chip, replace it with a new one, and repeat until the board under test worked or they swapped every one of them without finding the problem. (Then they had to start thinking instead of acting like a dumb chimp, but that's a different story. ) Anyway, often enough that worked. The problem was that they did this with boards powered on throughout. This was when 4XXX CMOS chips were common, so while they usually got by with it, there was a good chance that they caused damage that wouldn't fail completely until later. The point of this is: Don't ever remove a chip without making sure power is off and using a wrist strap. Lots of people get by with ignoring this, but in the long run it's a bad bet to make.
You might want to spray the rusted broken screws in the case with WD-40 and let that soak in for a while before trying the dremmel trick on it next time.
Or Liquid Wrench.
Classic computers left to dirty, break, or disintegrate always hurts to see. You do great restorative work, Adrian! :-)
NTSC or "Never The Same Color" as we call it in the PAL region ;) ... ahh good old times.
Also what we call it in the NTSC region... hehe... 😅
We did fine with NTSC. Less noise and a higher framerate than PAL, anyway.
@@infinitecanadian True, though they got the resolution in exchange. I lived through the late 80s and early 90s making the joke that we recorded everything on masking tape! 😂
While true, NTSC allowed WOZ's color hack to work allowing us to have color as early as the Apple II. PAL regions didn't get it on composite or if they did it would have only been on the IIgs or an adapter for the //c.
@@richfiles It was also easier to use in studios.
it can't be just me, who's face lights up when they receive a notification that there's another instalment from the digital basement of Adrian.
I absolutely love this channel.
With me it’s LGR...
A thought for the cloudy plastic on the keys, I've used a metal polish called Peek when I've had dull or lightly scratched plastics, and it polishes out the cloudy dullness nicely, usually that's oxidation of the plastic when it's that light powdery look, which polishing removes and smooths things out nicely... :)
Eek!! I would have done a chip reseating and got it working before a deep clean like that, and only done a dust removal (vacuum) first and a recheck. Also with those power supplies, you need to be really careful. Some of the rails are only managed with zeners and if they blow, you can take out a board (or at least a few chips). A single dry cap can throw all the rails off. Best to test against a test load block before applying it to a board. where I worked, we had a lab of apples + clones. The clone supplies were actually more reliable than the apple ones, those of which were often replaced by a clone supply for safety. The most common failures were the ram chips which always ran hotter than the rest so that was the first port of call. Best of luck!! looking forward to the next clip to see if it survived ;)
Dude! Goo Gone makes a great key cleaner. I let them soak in it overnight then rinse them under a small stream of running water. The dirt and grime practically fall off! Afterwards, I filter the Goo Gone and set it aside for re-use on the next project.
9:08 - I've tried a lot of over the counter products for cleaning plastics and really like Meguiar's G4116 Natural Shine Protectant ($5 in the car cleaning dept @ Walmart) applied with a micofiber cloth. Gently cleans without damaging/drying out the plastic and gives the surface that perfect satiny just-out-of-the-box look, especially on textured materials. Works great on car interiors too, of course.
For broken screws and bolts, a left handed drill can help if needed, if it grabs the screw in reverse it will tend to unscrew it, if not, it will drill it out. Just be sure the drill is well centered.
At the 6:55 mark you are correct about the Apple //e keyboard. The logic is all on the motherboard. If I recall correctly you can actually simulate key presses to some degree by unplugging the keyboard and jumpering the pins around.
I have an Apple 2e, Color monitor, and floppies that were in a threshing barn for at least 20 years. The 2e was not too bad but did have a fair amount of seed, husk, dirt/dust, and bugs. The floppies were really bad-off with dirt, mouse poop, urine, seed, husk bugs, and other unidentifiable's. I found 4 drives and made two workable. I did tear the 2e down and cleaned it good. There was also a C128, 1571, and Excelerator Plus. The 128 needed a good bit of cleaning, as it was near the thresher but the drives were near the apple 2e. That keyboard you had was clean compared to the 128's. They were loaded with years of crap! The 128 was spider central and it had so many bugs in it (hence the spiders). I took a lot of time with it and it still has some KB issues but now looks good for its living location. I had to reflow the power jack and switch, flush and clean (many times) the power switch. I never knew so much stuff could be in such a small space! The KB needed a few plungers 3d printed (I used tinkercad to make) I had to recoat the KB traces as they there shot in places even before cleaning. I just used an old #2 pencil and colored happily for over an hour. The PSU was dead as well and I used a 9VAC wall wort and a Hi-Link HLK-20M05 for the 5V and placed those back in the PSU case. I plan to recap it all at some point soon as well, but surprisingly they all seem ok but will do them.
@Adrian's Digital Basement The splotching is due to the oxidization breakdown of the plastic. The trick I used years back is a sealant for plastic car parts. Make sure its a nonreactive sealant.
Great cleaning job! I'm looking forward to part 3.
I used to work at an authorized apple educational repair center, we shut down the old apple repair service when apple shut down the program. We had tons of factory new inventory parts for Macs and Apple ]['s, Most of it went into the dumpster. I wish I would've kept it all, the owner probably would've said, take it if you want it.
VERY lucky to have an Alps keyboard Adrian! The Datanetics keyboards … replacement switches are hen's teeth. Datanetics is definitely more desirable among collectors, but Alps is more desirable if you want to be able to fix it. Me? I'm kind of in the modern Cherry-style replacement camp, if only because I'm interested in having options that don't involve finding dead machines to pick over for parts (or rather, the actual fear, machines that worked that were parted out and destroyed by unscrupulous eBay sellers).
Not only that, I'm starting to be interested in modern cost-reduced clones of the old machines. I think the biggest impediment before was that starting in about 1980 the machines started getting not only rapidly more complex, but also rapidly more based around custom chips that you just can't get anymore. It's bad enough there are so many standard chips you can't get anymore. But these days the tools to make them are becoming affordable and available to hobbyists. So now's the time to recreate these things if we want them! (And we do!)
Try a pair of vise grips if there's part of the screw shank still sticking out from the hole. Gotta be careful not to apply too much torque, of course. Outstanding channel and videos BTW! Thanks so much!
The manufacture date of the II+ main board is on the white square on the corner of the motherboard by the power connector. It's handwritten on one of mine ("8139") and stamped on my other one ("2182"). At 1:48, you can see that yours is stamped with "3382".
While I didn't check each and every IC, my 1982 board probably has a few more 1982 chips than 1981 chips and I also saw an 1980 date code. Maybe someone found a couple of old parts bins the week that your board was stuffed.
Older TVs, I'm talking up through the 1980s at least, had a dedicated circuit called a "color killer", which turned off the color circuits when a monochrome signal was being broadcast, improving the monochrome picture quality and eliminating any spurious color in the monochrome picture caused by interference. TVs of that era didn't have too fancy of filters to disable. I know this is a monitor, so a bit different.
I bought a phillips 17" colour in 88' for my amiga - they still make the best monitors and also for medical use....
Years ago (2007-ish) I picked up an entire school computer lab of everything from II Plus to IIe Platinum that failed to sell at a yardsale in Tennessee. The early 80s systems had a mixture of old/new chips, while toward the IIe Platinum it was mostly a newer / consolidated design. I don't know when they started consolidation, but if had to guess, 82 or 83. I had a bunch of expansion cards including some test readers that were used by the school.
When I collected micros, my favorite part was cleaning and repairing. Can't say I used them that much though.
Can’t wait for the next episode!
8:45 - Looks like Watery Soap to me........... :D
(Couldn't resist that Odd Tinkering reference!!!)
But where is the Ducktor?
I am so surprised to see you pointing out that 8T97. I just had to go see and yes I still have many of them dated 7912 and 7948 and also some other 8T series. Didn't really have any info on them back then when they were given to me as a kid to play with so I was curious about them for quite some time. Ah well, if you ever need one of those I can get you one :D
The mobo date code, shown at 1:47 is 3382. Right by the power supply connector.
The keyboard encoder was an AY-5-3600 by General Instruments which was a purpose designed PMOS device that used a couple of ring counters, a comparator, and a 3600 bit ROM to scan for switch closures and generate keycodes. As a side note however... by 1983 GI was selling the KB3600-PRO which was a PIC1650A microcontroller with a mask ROM for emulating the AY-5-3600 while adding a couple features.
Those 8T97s are the address bus buffers and blew occasionally when other address logic went up so I'm not surprised on the different chips. In the factory, all three were parts from the same feeder.
Great videos series, thanks for sharing-I'm the original apple II kid, but personally I wouldn't have cleaned it before finishing the trouble-shooting since from my experience, it's too easy to introduce another issue thereby compounding the repair process. Your initial smoke test symptoms: power light on, screen filled with gibberish, no beep, indicates bad MOBO or PS. Since you tested the PS, the next thing I'd check is the 74LS74 power reset chip, then the crystal, or one of the 8T97 chips.
I remember the first time I tore a keyboard apart to repair I did not think to map out where each key went so I had to use my type by touch to remember where each key went. Basically remembering what each key I hit with each finger. That only happened to me once.
I've had good luck removing seized, broken-off screws with a left handed drill bit, for what it's worth. Harbor Freight sells a set inexpensively, and for how infrequently I use them (like, 1-2 times a year?), they've been fine.
Have you tried a Dremel with a buffing wheel with plastic buffing compound to fix the space key?
nice adrian your the best on outube i never get bored watching your vids
Nice!!! Huge fan from Brazil🇧🇷 keep the awesome work! 👏👏👏
Finally good to see you working on apple 2 systems. Hopefully you have more as they were the gold standard back them.
22:42 Ooh, shiny!
Looking good, Adrian! Love these in-depth cleaning vids. :D
And that monitor brings back some feels of the mid-80s for sure!
5:47 This is how a dremel should be used to get a screw out... I´ve seen worse in the not so distant past on UA-cam ;)
Let's not give out any names...
@@goeland4585 Where's the paperclip....
@@goeland4585 you mean like Dave? ....ooooops!
GORF poor Dave.......
@@jameshearne891 Priceless prototype? Let me just short line to neutral
I used to have a switch on my chroma signal to my 1702 so that I could BBS without squinting so much. It worked a treat!
The marks on the side of the keys is normally due to grout from fingers. The mix of dead cells, sweat and dirt act as an acid and discolour the plastic!
As for a dirty machine - long way to go. I had machines returned to IT where you could not see the chips on the board from the dust and bits - yuk.
Worse keyboard was one from a home office set-up where their youngster had an 'accident' without nappy (diaper) and they returned it to the office for us to clean - yuk yuk yuk.
Always learning so much, thanks a lot Adrian ;) Btw some day you should do a video on how you setup your basement, with the tables and how you are evolving down there ;) would love to know more about that.
You should have dropped some WD40 on those screws and given it a few hrs, may have worked them loose (it's what it's designed for)
Actually, original purpose of developing the WD40 was not to loosen screws. BTW it's still great to do so.
@@Kedvespatikus I didn't mean it was specifically developed to loosen screws... but more of getting down into rusted areas to un-cease and lubricate, and such..
Kroil might be a better choice, but if it the bolt was already rusty and someone used excessive speed/force putting it in there may be no removing it. After trying a few things, it might be easier to drill out. There are bits for extracting bolts and remaking the threading. Not particularly expensive either.
@@Ghozer WD-40, short for "Water Displacement Formula 40" was developed for application on rockets to protect them from corrosion by Rocket Chemical Company, later renamed WD-40 Company. It was only much later discovered that WD-40 had also a much wider variaty of use cases, so they began to market it first towards businesses like airlines and general industry and later also the common consumer.
WD-40 isnt a lubricant, its sole purpose is to keep water from a surface that it was applied to for the short term.
they added a beefier spring inside the reset key in your model as well. I remember the reset key frustrating me when I was a kid in school cause it would reset out of the game as well
As I commented before on the last board you washed, never use tap water from the faucet. Tap water has too many things into it that will ruin a board. Back then you stated that your water is filtered but that is not the issue. The issue is others copying what you do and then ruining their boards because their water is not filtered. (My NYC tap water will leave a board wrecking white residue if I dare wash a board in NYC tap water! )
If you must wash a board use and demonstrate using distilled water from a jug.
Thank you.
I totally agree with you. His lack of ESD precautions makes me wince too when he is handling components, considering how old machines like that Apple getting rarer and rarer you would think people who have them would take every possible care in when handing chips and motherboards.
Sharpness is increasing or decreasing the highest frequencies of the video. As an analogy, in the audio realm, it's like a treble control. Jump the frequency up a couple megahertz,. and you have a sharpness control. The highest frequencies of the video signal contain the detail information. Boosting it too high can cause "sparkling". Decreasing the sharpness, removes some of the detail. The key to sharpness is to get the best signal without sparkling.
Man i wish you had a pair of Vampliers for the broken screws. Those type of pliers saves my butt all the time
I have a couple of original Apple 2+ they were one owner. Both have a rather wide range of date codes on the IC
I love the monitor. Pitty the clean up of the motherboard made it worse. It's amazing how often that happens. For the past 6-7 years, if I plug something in and it works then I don't mess with it. LOL. :) Looking forward to the next part.
Actually you'll see in part 3 it's not as bad as it seems :-)
@@adriansdigitalbasement Bit of a relief.
alot of people believe Apple only puts 'Premium stuff' into their computers, but that is not the case at ALL! This is very normal for Apple II's. All of the Apple II's I repaired had a crazy mix of chips.
What a great video! Adrian, have you thought of doing a video on "monitor basics" both for color and monochrome displays? You have such a deep level of understanding of these concepts, and it would be fascinating to learn more! :) Keep up the amazing work!
Definitely!
Agreed, it would be really handy to have some of the stuff covered over time rolled up into more general and complete 'how to' videos
Adrian: Clearly typing
Captions: *APPLAUSE*
Maybe someone was trying to fix this computer by swapping chips.
Great vid mate. Great Sunday morning viewing. I'm sure vinegar in the jar was a hit for Thin Lizzy.
To add to Greg Gall’s comment, the PC board manufacturer usually adds a date code at the copper level, (if not, sometimes as part of the silkscreen level), usually in YYWW or WWYY format.
almost 10k views in less than a day! you're killing it, brother!
That is so scary to see you washing motherboards with soapy water 😅. I know that you know what you are doing but I never ever dare to do that by myself. Great video once again.
My open bench liquid cooled VR PC started leaking during a beatsaber session one day so I just washed the motherboard and GPU in hot soapy water and dried them, still works great.
Also revived a lot of spill damaged laptops at my old job with the same method.
Maybe a dust-short served as an alternate route for a broken trace?
i was expecting a fixing video.... arrg ! one more week to go... this drive me crazy... nice work adrian !
Yay! 5.4" floppy of Wizardry! :D I got a PC Dos version myself. Absolutely love that game.
Don't know if you have this stuff up there, but Nifti is stronger than Windex. Next stronger is a good brand Sugar Soap. These ammonia based cleaners don't need much if any scrubbing. You could also try bleach.
Plastic can be polished like any car paint so for the key sides you could use 2nd cut and polish, which is slightly abrasive to clean and smooth, and polish to make it glossy. Cutting compound first if it's really bad.
CLR eats rust, so it might have got the rust out of the broken screws threads so they can be unscrewed. Vinegar is milder, but might also work.
We absolutely need to call the Ducktor.
Also, in my experience working in an electronics manufacturer, it’s not uncommon to have multiple vendors for a given part, so some of the vendors likely had various lots of a given part, especially if they were a second-string vendor (buying up leftover lots from the manufacturers when certain products get discontinued etc.). As a case in point, one board my company built up until the mid 2010s had a fairly scarce IC, and the lot that was located to allow us to keep building as long as required had a 1981 date code! So, the variation in date codes would be somewhat reasonable for a vintage 1983 Apple.
Great stuff as usual Adrian. Nothing like cleaning keys while watching shango's greatest hits. "Needs more twerkulating..."
Hey Adrian, some chip manufacturers stamp some info like date codes and type also on the underside of the ic package. I lately found that on some fake AY-3-8910 that had suspiciously new looking topsides on the underside still had original date code and YM2149 stamps on. So check the underside to see if this can clear things up.
Fantastic looking board, It looks like the difference between a top end luxury car and a bottom end commuter car. "Well Made"
Hey Adrian, nice videos. I think you have previously said you come from a professional IT background. If that's hardware v software then you would have had ESD precautions drummed into you like the rest of us have for the past 40 years. It would be great to see less comfy rubber mats and more ESD precautions on these treasures. Cheers.
13:33 Newer Apple II plus models had a switch at the top of the keyboard just inside the case. When activated you had to press control with the reset button.
Adrian, a date code span of 12-15 months wasn't unusual in the Apple II+. This was due to variations in the supply chain, where some of the chips were available in large lots (and thus an older chip might make its way into a newer unit) and other chips were available in smaller lots.
However, the 5-year span of date codes in this example is suspicious. The keyboard and encoder, and the layout of the motherboard, make it clear this is a late II+, probably a Rev. 7 board, so that 1978 chip is way out of place. Perhaps this was used as a donor machine to keep another II+ working, and the "bad" chips were put back into the donor machine to be "tested again later" --- without marking them, of course. A terrible practice, yet one I have encountered before.
It will be very tedious, but since the II+ has mostly standard TTL chips in sockets, I encourage you to simply test every TTL chip to determine if they are good. This will also create the opportunity to reseat all of the chips. Don't assume the first bad one you find is the end of the story. Until you have verified everything, treat it more like a bag of loose chips than a complete computer.
As others have pointed out, you can also try booting after removing all but the Fxxx ROMs, you can remove all but the first 16K of RAM, and you could swap in another 6502 processor from your stock (or a Commodore disk drive).
Have you tried to use a ultrasonic cleaner for cleaning keyboard keys?
For removing screws, you might want to get a set of screw extractors or EZ-Outs. They are a little like taps, but left-handed and wedge in the hole you drill. There are left handed drill bits that sometimes will spin out a screw on their own, too.
Screws stuck in those brass inserts are a pain to get out.
I think you need to populate the missing DRAM IC. The chip is normally removed and put on the memory extension card. This trick allows the extension card to gain access to DRAM timing without having to add additional logic.
Or put the language card back in.
Just my guess though as I have never serviced them before.
Unless you count hitting them with the _Fonzie fist_ to get them to boot (due to bad socket connections on the mainboard, did that lots on the high school Apples, in the before times.)
Cheers,
The keyboard sounds nice.
May I suggest re-seating all the socketed chips. Those cheapo sockets can develop open circuits over time!
I never used the Apple II+. I used the Apple IIe in high school.
stuff carried over from telegraph machines the G key says BELL on it. They press a ctrl or like an alt key on the telegraph machine to ring a bell on the machine you are sending to. maybe tell them a message is coming through or ending of a message etc.
I would think that if it was worked on, the repair shop may have used either what chips they had in stock, or what ones they could harvest from dead systems. That would explain the wide range of much older chips.
You sure you always have the 'Notify subscribers' checkbox enabled when uploading videos? Only cos I don't hear _anyone_ else complaining as much about the YT notifications... In fact, it's one of the only things I hardly ever hear anyone complaining about where UA-cam's concerned... Also, I do receive your notifications most of the time, so I figure this little checkbox I'm referring to is enabled the majority of times. So... That's a thing...
Apart from this, I really liked this vid!
You could try soaking the screws in ACF50 after the vinegar. Its an anti corrosion substance used in aerospace, so should do pretty well.
Great video I really enjoyed it, fascinated to find the true date of this motherboard
You might consider a vibrating tumbler with walnut shell media to clean your screws. They can be found on Amazon.
I prefer using citric acid with few drops of dish soap instead of vinegar. It takes the rust off better and is less damaging to healthy metal. @10:45 When you were cleaning the keys. Was this shango066 repair video that you were watching?
Can't wait for the next one. Keep up the awesomeness!
Cliffhanger!!! Great video Adrian.
Wow both Adrian's digital basement and Ben heck hack on the same day? It's a good Saturday.
You should probably put up a trigger warning when using a dremel. The mental scars haven't fully healed for a lot of people who witnessed that IBM prototype getting butchered by one.