EEVblog 1425 - Fluke Repair 2 Electric Boogaloo
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- Опубліковано 29 лис 2024
- Part 2 of the Fluke 23 multimeter repair by digging into the bunker meter archives from episode #84
Experimenting with alfoil
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It looks like the air creeped under the polarizing filter, oxidizing the silver layer. In the center oval, more or less where the lcd pressure kept the two layers pressed together, keeping the air(and thus the oxigen) out.
Yep, this seems highly likely, perhaps in tandem with sunlight damaging the adhesive layer over time and allowing air to make its way in there in the first place.
As an aside, Dave says "You can design LCDs so you don't have black segments, you have a black background with a white segment or whatever". This used to be the first thing I'd do with my calculators as a kid in the 80s -- take them apart, flip the unbonded polarizing material and hey presto, black background with white letters.
@@gweilo8888 it doesn't need degraded adhesive. Just the exposed edge of the silvered layer is enough. The oxidation will creep through the material. You get similar with old photographs where the edges weren't sealed fully.
@@allensmithphotography The only reason I made that assumption is because otherwise they'd *all* be like this. I have numerous products of similar age whose LCDs haven't degraded in this manner.
@@gweilo8888 and that's very true that not every LCD of this type doesn't have this issue, just like not every mirror degrades the same way. It could have been that LCD didn't get as good of an edge seal. I know before I used photographs but mirrors do the same thing over time. And just as you mention not every mirror degrades to the same extent as every other just as the LCDs in this discussion
Any half decent electronics engineer should know this is the number one symptom of an LCD that is low on magic blue smoke, disappointed you ruined it instead of refilling it but at the very least it was interesting to see that your hack did kind of work, it was at least a cheap fix, magic smoke can be very expensive sometimes.
Someone: "Tell me you're experienced without saying a word."
Dave: *Begins to show an entire collection of multimeters dating all the way back to the Roman ages
Yeah ha ha wish my multimeter bin was that full
"the alignment does not matter", but every time I tried removing an LCD with a zebra strip, some of segments were then missing.
Maybe it just got dirty, but I don't think I've ever managed to reinstall it properly.
Even when Dave puts it together at 9:50 it's messed up and missing at least one segment
If I don't need to replace an LCD, I leave the strips connected to the LCD. I've never had this problem with the 70 series, but the Fluke 10 series LCD contacts were fragile and were known to lift/get destroyed. Orientation is important, as the old boards had solder "blobs" of varying height and width, and they'd take a permanent "set" and not make good contact if placed incorrectly. I've been known to have to try all 8 combinations when I forgot how they went.
The only time I've had success reassembling zebra strip LCDs is if I clean all the pads and ITO display contacts with high proof iso before reassembly and make sure the bezel/housing that holds the sandwich together is as tight as I can get it. Any little bit of dust or shmoo on the contacts will leave a dead driver, and if it's not down tight there will be whole spans of dead segments.
@@treelineresearch3387 yep, 99% ipa makes zebra strips a breeze!
@@pyromen321 another vote for the IPA here, wish I'd known that as a kid messing with old digital clocks etc, could've saved lots of frustration... (take away from this, kids, turning to alcohol IS the answer sometimes)
the adhesive they use to stick the polarising layer eats into the foil with UV activation...
nice collection of meters!
Zebra strips work great to repair the Fluke 120 series scopemeter LCS’s. Only works to fix the horizontal lines. Just remove the hot bar contacts and replace them with an appropriately sized zebra strip. I used kapton tape pulled tightly from the top LCD glass to the PCB in order to keep pressure on the the zebra strip. Alignment is tricky though. I had to message the zebra strip to one side or the other in order to get the contacts aligned due to the fine lead pitch on these displays.
Well now I'd be quite interested to see a troubleshooting session with the other meter, if nothing else just to see a damage report of what happens when you blow the ass out of it
I am a bit of a DIY'er and laid my own laminate floor panels.
For the Underfloor I used adhesive Aluminium tape, ultra smooth and reclective. That would be suitable!
I used to mess with LCD's a lot as a kid (even tempts me now, as a grown kid!), flipping the polarising film to make a negative display on old watches and stuff like that. Just seemed super cool back then how you could make such a huge difference to the look of an old Casio knockoff just with a steady hand and no money in.
I believe that this happened to the adhesive due to exposure to UV by sunlight. It's a common point of failure for old nintendo gameboys for example
I was trying to remember where I have seen it before. Gameboy.
Good to hear the word Zebra pronounced properly.
None of the zeebra rubbish.
As an EE/MSE person in microelectronic Fab this reminds me of making a silver mirror with silver nitrate. To demonstrate the Tollen's reagent, you can crash silver out of silver nitrate and make mirrors! I did this in highschool chemisty, but my beaker is basically brown now. I don't know if it's an oxidative state (a patina) or somehow it form a nitrate in atmospheric conditons (the nitrogen tripple bond is >9 eV).
Bit of mucking about. But how about using Kitchen foil as a silver backing with a bit of polarising film. Held together with some photograph mounting adhesive. The polarising film can easily be obtained from any lighting outlet especially Film and TV suppliers where it's a dime a meter. Just for fun.
Try some polarising film from an old lcd monitor cut to shape?
Yeah, was thinking of that, and I kept a big sheet of it, but I think it got lost or tossed in the move.
@@EEVblog There is a Samsung donor LCD panel in the room of surprises though, perfect, as you have more than one chance of getting a big enough film section.
You can also use an old TV LCD that has a broken glass, it can peel off the layers of polarizing film and successfully repair a damaged polarizer, I hope you can read this Dave, greetings from Mexico.
Brings a tear to the eye. I've been down that road.
I'll mention that Fluke did change to the clear windows with no model designation, with the designation moving to the LCD surround, but they had retrofit kits for the older meters with a printed LCD surround and clear window. After installing the new surround, one could purchase a new window when necessary. Sadly, Fluke doesn't offer these anymore, but most just re-polish existing windows with good results.
I'll also mention that I've only had to change a handful of zebra strips, but it's important to put them in the way they came out if the contacts are the raised, solder type. These differ in height, and the connector takes a permanent "set" and won't make good contact if placed in a different location or orientation. At least one crazy person has had to try all 8 combinations (as it's obvious which side is toward the LCD0 when he forgot where they went and in what orientation.
As an alternative to replacing the squished zebra strip, maybe add a bit of solder to the PCB pads (which look like they're already covered with a layer of solder, HASL finish). The addition of a thin layer of solder would change the topography to deal with the "set" and the added thickness would slightly compress the strip, mayb resulting in an improved contact.
You could turn the meter into a special one for measuring secret voltages inside secret circuits. Just remove all the polarizing films from the LCD, stick a piece of white paper to the back and wear polarizing glasses.
I remember doing that as a kid with calculator and sunglasses.
The "magic" calculator.
I remember seeing videos on UA-cam about doing that to a computer monitor for maximum privacy. Basically take the polarizing filter and stick it where eyeglass lenses would go. Your monitor will then appear bright white without the glasses (and correct angle)
Sounds like a perfect magical meter for the magical audiophile industry!
Your age is showing there, Dave!
You don't need to replace the back of the meter to fix the stripped screws, you need to replace the front case, as that is where the threaded part is...
Was thinking the same.
D'oh
17:35
that is the same one from
EEVblog #84 - High Energy Multimeter Destruction@9:13
You'd need to bodge in some contacts for the rotary switch, probably. As well as populating the missing parts.
Put a light source behind the backless LCD and make a projection meter!
Having Mrs. EEVblog explain the discolouration would be super interesting, along with why some plastics in older gear turns yellow.
Bromine?
Perhaps a bright white piece of paper or dual layer paper will reflect even more light than the stock greyish silver and be even more high contrast? Try it :)
In gardening plants they discuss if mylar, white paint or aluminum foil is the best light reflector.
I think pearl white paint on a plastic plate background might look beautiful. And one could make a mold and cast a new pearl white rubber shock protector and you get a iFluke..?
Oh no, what have i done.. started a contest of who has the best modded Fluke? :)
Great video. Alibaba and other sell reflective film and sheet polarizer for LCDs. I have seen people mod LCD watch displays with this stuff. You could likely fix the original display with some. Seems pretty cheap.
Foul works but it aren't just the lack of polarizer, but the layer thickness/flatness to the LCD screen.
I had to hack in a modern lcd in a fluke 8010A couldn't get hold of any replacements
If the resistor is open how could you have burned yourself on it? It would not have produced any heat as it is open therefore no current should have been passing.
Going to guess the analogue front end has shorted a power rail to the input, and the shorted MOV is allowing the input to be hard connected to ground, thus the low value resistor there is passing 9V to ground, and heating up. Likely the resistor was just some random one, or got the snot blown out of it, so it shorted out from burn debris to around 100R.
I have had to add an extra layer of rubber (black electrical tape) to the LCD in some cases to get to conductive rubber strips to make good connections to the LCD in past years.
You can just put 1 or 2 piece of white paper as backing, it will look better
That was my thinking too.
I think itd be kinda neat to print custom designs on the paper. Itd be like wallpapers. Practical no, but pretty neat
That was both informative and a repair which is what people like of course.
Years ago I didn't know how zebra strips worked then I looked at one closely and figured it out.
I had a problem with the display of a chinesium meter. It's reflector oxidized and I stripped off the whole lot of films from the screen. Now the unit is operational again, but it's LCD suffers from the Salazar's Curse
The clear outline segments look pretty cool.
I was in component level repair with Telstra 20 years. We had this prob with our Flukes. Fluke said it is because these are not Tropical Displays, which we need in Australia. They supplied us with replacement displays. Regards Norm in Sydney......
I drove over my 70 series with the car, I even thought to myself; don't leave it there you'll drive over it.
It still worked but the display was cracked, so I phoned Fluke for parts, they said "...and it still works? Can we have it for our display?"
"No you can't! Sorry."
They sold me a new display.
Getting a new display for and old series 10 was more difficult.
The polarizers back and front are at a 45 degree angle, or else you wouldn't be able to see anything from the reflective surface, plus are like that to enhance contrast. But I'm going from the top of my head here so check!
I'd buy that. The polarizer broke cleanly at 45 degrees when he removed it.
@@martinmckee5333 I don't know how, or rather can't remember, how they are constructed, maybe has something to do maybe not. Probably that's some kind of plasticized crystal, it's not irrational to think that mechanical properties somehow match optical ones, either vertically or horizontally to the optical axis.
@@TrickyNekro it could be that or it could be a simple scribbed polarizer.
@@martinmckee5333 you mean wire grid polarizers?
Pick up one of those dumpster monitors and steal the polarizer out of it - many of them have a large, loose sheet of polarizer film.
Alternatively, get some GameBoy polarizing film from eBay - you can get loads of it for a few bucks. Or just wear polarized sunglasses!
I have a sorta sad story regarding the Fluke 89 that served me well for over a decade, right though two engineering degrees as well.
I made the silly mistake of sending it back to Fluke Singapore to replace the dying LCD and they wrote back saying since the unit it no longer produced they would let me buy a replacement. The cost to DHL it back was almost half the cost of a new one so they disposed of it. Blimey! Never do that, be wiser and fix it yourself. I would never have sent it if I knew this would happen. Bummer!
It's kind of them to allow you to buy a replacement meter
@@Soapy555 right? Haha!
@@Soapy555 their phrasing in their email was exactly that. They’ll “let me”. Sheesh!
@@bsodmike Yeah, I assumed that's probably how they worded it
RIP Fluke 89 - you will be sorely missed
Just an asside, you were missing some segments because of degraded elastomeric strips. They sell replacement strips for about $20, However, I’ve fixed two Fluke displays recently by simply cleaning the edges with isopropyl alcohol. Anyway, great video as always!
Dave, I have a Fluke 87 True RMS meter, it's 30 years old. Within two years of owning it, the LCD Screen started having fading issues where some of the digits would just start to "disappear". I contacted Fluke way back then, and they said "Oh, that needs a repair, it is $x plus shipping to/from us". The cost of the repair was actually MORE than the cost of a new meter (my cost via a supplier discount I could obtain).
I obviously declined, and cracked the case, pulled the screen out and reset it. Put it back together and Robert is your mother's brother...IT WORKED. Well...for about a month. Every few weeks to a month I have to tear the meter apart, pull the LCD off and re-set it back into the housing.
Any ideas of how I can PERMANENTLY fix this? I really don't want to buy a new meter since this one works perfectly except for the PITA of resetting the LCD every few weeks.
You may need the plastic piece that holds the LCD in. The plastic fingers get weak, and often break off as well. I apologize, but I can't find any of the ones I have, and I can't find the part number. I'll edit this reply if I find it.
EDIT: P/N is 619632 for all 87s except the IV and V. I'm not sure if this part is still available from Fluke. Even though it's not WrekDiver99's problem, other's reading this may need one. There were some e-bay sellers selling these, but it's been a while since I searched.
Other possible problems are the contacts on the PCB. If they are METAL, you can clean them with an ordinary pencil eraser, then some quality contact cleaner to get the residue off.
Another possibility is the front LCD surround - if it cracks like Dave's did (yes, I've cracked many as well) it won't work.
I recommend visiting the EEVBLOG forum, there are people who are very good at fixing meters there who may have better/more advice.
That should have been covered under warranty.
@EEVblog...you're a funny Aussie Dave. One would think so, but Fluke stated my issue sounded like "normal wear and tear" which is "not covered under the limited warranty" It is what it is.
I lost a lot of respect for Fluke when I got that note back stating it would be between $175 and $200 USD to "repair" my meter.
I paid around $180 for that meter via the supplier and quantity discount (all of us jumped at the price discount we had gotten so as a whole over 50 were bought by the engineers and electricians. Back then though, that was nearly a weeks salary after taxes (I wasn't making squat as an engineer in 1991...all of $10/hr)...
It is what it is...I just pop the cover and move on.
@@excavatoree So it's all intact, all of it. I will look to see if it is dirty, and I'll clean the contact points as well. The cover snaps firmly in place, and it works for a good 3 to 4 weeks, sometimes longer, sometimes shorter before I have to do it again. I might jump into the forums (I do not like forums, 17 million discussions going on at once and you can't find what you're looking for (with the search features) and then you ask the question and get jumped on by 100 people screaming "USE THE SEARCH FUNCTION IDIOT"...so...yea...not sure if I will or won't go there...LOL.
@@WreckDiver99 Are your LCD contacts (on the PCB) gold, solder, or the carbon type?
Entirely possible the structure of the LCD itself and the crystaline structure is acting like a freznel lens, and causing the silverised coating to oxidise. If I was to have a guess.
The burn pattern suggests such, you might be correct, or maybe it was Oxygen leaking in. Awesome assessment Data!
This unit is a venerable Fluke 23 series 1. I own a Fluke 21 series II and is perfectly operational
Bringing back nightmares with zebra strips, when I used to take apart my LCD watches in the 80s when I was really young, and had to hide the inevitable broken segments from my parents!
1/4W and so hot seems a lot of current is flowing when it's on . The probable cause of failure of the original resistor is somewhere else and its worrying
It does look like "water ingress" from the shape and distribution of the discoloring. I don't think that it's related to sunlight as such; if so, it would be more uniform. Maybe UV makes the process faster or more pronounced, but it clearly is "eating into" the display from the edges in, so something in the air (gas or moisture) or direct exposure to water is my bet. 🤔
You can get replacement polarizing film and you just have to figure out what angle to cut the rectangle out and it works great..
Since we're discussing our first digital multimeters and with the recent passing of Sir Clive, it reminded me that my first digital multimeter was an LED Sinclair multimeter.. I think I still have it somewhere in a box in my own bunker...
I got two of them out of my other box of multimeters!
The failure of the reflective is probably similar to the failure that bullet proof glass has after years. Bullet proof glass(at least the old stuff) becomes cloudy and loses its transparency. Has to do with the adhesives used to laminate the glass.
Looks like simple oxidation. I see the same thing with old glass negatives I work with at the library. After a few decades even the best seal will still allow enough oxygen to enter to start the process.
You totally missed an opportunity here. Getting a new background polarizer on and coating the backside with a mixture of luminous and neon pigments wold have been the first stage of upgrade techporn and could have ended in engineers drool by 3D printing a new stand to fit an extra tritium light with a cadmium sheet as back reflector behind the upgraded LCD :P Making things better than they were before isn't just a sport it's a way of life. We're a lot of Tim Taylors out here ;)
likely oxidation, or if its silver based, sulphur. it diffuses usually through the glue
Aluminium sputtered foil on polyester sheet, the uncut edges slowly diffuse oxygen through, and create the ring of oxide as it slowly diffuses through from the cut edge.
I had an LCD go bad in a Fluke 8050A-01... sad to see it slowly fade, and bleed. Naturally, Fluke had no spares, and the otherwise perfectly operating meter with dB math and battery option became junk.
I think you can replace the LCD with an LED display, if I remember correctly. There was some information about this on the internet somewhere. Damn, now that I think about it...where is my Fluke 8050. Haven't seen it since I moved! Grr!
The light hitting the glass at an angle slightly polarizes it, that's why it works better there.
I saw a story about a guy who removes the LCD panels from pregnancy tests. Then he makes tiny video games. He plays Doom on a pregnancy test. So you could use one of those panels for this repair, you’ll just have to squint a little.
The silver coating oxidized. Its like a mirror. I have never found a perfect replacement for it online.
The one and only time I ever removed an LCD, I could never get all the contacts to contact again when I tried to put it back together. It never worked properly again :-(
-Matt
Use silver spray paint on the back of the LCD
This is exactly what we used to to back in the late 80's. Taped off the edges, and sprayed them with a few coats of aluminum paint Polarizing film on the front. These were for outdoor instruments, so we would glue ceramic heaters on the back so the display worked in the cold
The DMM was left in direct sunlight for an extended period of time, and actually got "cooked" by the UV rays of the sun. Very common failure. Fred
LCD issues aside, that 23 still seems like a sick puppy, display jumping around between negative ohms and "OL". Was it really that sensitive to touch? I'm working on a similar vintage 77 that's acting the same way... really jumpy and flakey even after fixing the 1k fusible resistor. I'll look at replacing some of the caps next.
9:22 thats epic! id say, cool idea to make it look cool, lol
tin foil adds cool look!
I dare say some aluminium tape or something would work with some double sided tape and a replacement polarizer off a donor or ebay
A golden opportunity missed to fix it with a piece of bubble gum wrap instead of aluminum foil. More reflective, fewer creases. Would have given new meaning to the expression "fixed with gum and baling wire!" I'd have also fixed the cracked bezel with a bit of black CA glue just because I'm OCD that way.
Gotta say that outline look is pretty cool. Not very functional, but still cool none-the-less!
Excellent video! Always entertaining and educational!
Whenever I tried to reassamble a LCD with these zebrastrips, I always miss some segment. I tried this on many screens over the years and still not one works perfect after disassamble.
So I kinda hate 'em :P
I still use a SOAR 5430 as my standard bench multimeter, they were great.
So cool seeing stuff I work on being shown on youtube lol.
I have a mint Fluke 75 and its a completely different beast. Excellent quality
now I dunno if I still have em but I had a box of a half dozen parts of these:P(military throw away material)
It's happens because the glue not UV resistant between the silver mirror tape and the LCD glass... Just UV tolerant until them reached limits...
Durring a lifetime normal use, indoor a lab or workshop get nothing, but durring outdoor using also get just some exposure... But if you leave one or more days long on a direct summer sunlight... Yeah... It's like 20y long normal everydays exposure for it, what is definitely abnormal :)
Same things happened with oldschool handy tetris games, gameboys, or just a digital nightstand clocks what directly got the mornin' light :)
Also the UV light cause heat, heat generates not just oxidation but chemical gas as well, and of course the glue getting liquid again and deforming the homogeneity of layer thickness and casue these "fancy" effect....
Looks like it may have spent a lot of time in a corrosive atmosphere, like maybe at a sewage treatment plant or around sulfuric lead acid batteries.
Even if that '70 isn't fixable, it might be interesting to try swapping the ASICs to see if those still work. Could be worth a pretty penny, since they're made of pure unobtainium.
fluked it !
19:18 If you look closely, you can see that the “new” LCD’s backing is starting to oxidize, too.
Looking through all your videos on soldering stations and I don’t see any on induction stations like the hakko FX-100 or the metcal MX. would love to see you do a video on that technology
I have an old electronic unit with such type of lcd and it became full blackened in some spots from exposure to the sun in years; can anyone recommend specific materials to fix it?
Id love to see a repair of the other one !
The aluminium foil looks like aluminum foil to me! The good German aluminium foil is flat without any embossings.
The cheap British stuff also...
its silver oxide, which is black. looks like oxygen got in and likely UV radiation made it oxydize. you need the polarizing filter coz otherwise after reflection you cancel out the polarization in the LCD, theres no such effect before putting in the backing.
Those outlined digits would look cool on a watch.
i dont thing there is the space is there, im curious about modding a backlight into it???
Forgot to comment on the first video, but great comment as always Dave. Love DMM videos. Addendum: I appreciate the part number on the LCD starts with JF
Where did you buy the yellow plastic screwdriver/lever things ? And what are they called?
white paper would work behind the lcd, i feel like iv used a business card before i cant remember what it was on tho
could try reflective paint or tape, the types used to reflect at night
Parts pile to the rescue!
I learned something about zebra strips today!
Now use polarized sunglasses and the screen gets better 😉
On my old phone i remover one polarizer layer and then you could only see the screen with polarized glasses or film in fromt of it
Oh Dave, why don't you creators ever listen when I scream "Don't do it !" at my screen. It was a beautiful symmetric fault without consequences.
You need to clean the adhesive off the back of the lcd
Al-foil has a shinny side, but I would go for a chip packet inner foil.
How about a think, actual mirror cut with diamond tip?
Sir I could use the front case and knob assembly if ur willing to part with it
I think you got burny resistor because you have nothing less than a "professional duracel battery", I hope is not a leaky one too. ;)
There has to be a modern backlight that would fit it. Something like what they put in old gameboys
Hello David, Great videos! I am particularly interested as I too have a Fluke 73. It picked a fight with the concrete floor but the floor won, so the casing is in pieces. If you have no further use of the Fluke 77 casing, would you be interested in selling it? BTW, how do you send PM with UA-cam? Haha, have a great day.
Hi Dave love the repair videos would like to see if you could populate the series 2 and get it working as like the other one think that would make and interesting video
Might be interesting to modify it to have an electroluminescent backlight, just for kicks. Timex / Fluke crossover episode.
If backing is made of silver, than it must be sulfur oxides. (guessing)
Try it with white paper 👍
13:39 Is your cousin BigClive? He is into that pinball stuff.
Could you make the 70 also working?
could have just scratch off or tape over the label on the series 2 lcd module.