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/me is having missing row issues on an 84+
i've opened it up and removed the foil. what next?

oh, and, on a slightly related note (brought up by other discussion in this thread), what should i get in the way of a multimeter?
I have a very nice Fluke 79 multimeter, but those are quite expensive indeed. RadioShack has some multimeters that are decent enough for a Jackson or two. Anyway, missing rows on a TI-84+ means that the very fine-pitched cabling that goes from the display driver LCD (which is embedded on the flexible PCB/plastic that goes from the mainboard to the LCD) and the LCD itself has faults. These might be tiny fractures in some of the traces, or they might be points where the cable is coming unglued from the LCD. Even with much work, I have been unable to fix this problem. I've tried all kinds of combinations of heat, pressure for varying times and intensities, all to no avail.
wellp, i succeeded in disconnecting the power entirely somehow Razz
everything else still works, though, so spare parts pile it is.
Does this technique fix when certain keys do not work or does that take something else? Do you know how to fix that? Graphing Calculator
I love it! I've just spent a most enjoyable lunch hour reading about the fascinating repairs to sick TI calculators. Wonderful. I was so sorry though that 'john massey' did not have a successful outcome for his repairs. Delightful posts. I look forward to reading some more like this and, hopefully, reading about successful repairs.

Alas, I can barely fix my pencil sharpener, let alone an electronic TI calculator, but I love to read about electronic repairs and I am so tempted to buy a busted TI 83 and take it apart just to see its innards. And, who knows, if I have a beverage of crushed ice and vinegar, I might even attempt a repair myself. Cover my back boys, I'm going in...

PS
The photos add to the singular pleasure of reading about the repairs, but a video would be nirvana (even more pleasant sensations in one's popping crease). Thank you so much KermMartian! And well done to all those other fearless fixers of TI calculators. I salute you! Very Happy
WoCo2016 wrote:
Does this technique fix when certain keys do not work or does that take something else? Do you know how to fix that? Graphing Calculator
No, for that you need to trace the traces on the PCB from the key in question to the ASIC. You will likely find an open circuit somewhere along the way. My preferred repair method for that is to use sandpaper to expose copper on the traces on either side of the fault, then carefully solder 30 AWG wire across. Sometimes you have to go between the two sides of the board, which can be tricky.

Flinty: Glad you enjoyed the guide. It's never too late to experiment with some repair work of your own.
Thanks you so much Kerm. I'm having another problem now. When the batteries are inserted and BSOD immediately comes up (without pressing the on button), the technique you came up with does not fix it. I've been trying to figure out how to fix this but cannot come up with anything. Help please! Thank you.
Can you be more specific when you say "BSOD"? Do you mean a fully-black screen? Or something else?
It is a fully black screen as soon as you place batteries in the unit. Also unable to turn off the calculator when this happens. Thank you.
WoCo2016 wrote:
It is a fully black screen as soon as you place batteries in the unit. Also unable to turn off the calculator when this happens. Thank you.
Hmm, that sounds to me like you either have both keypad and LCD damage, or some deeper damage that I can't suss out easily. Have you tried connecting your calculator to a computer while it is "on" and seeing if you can view its contents via TI-Connect? That's my standard method for distinguishing between dead LCD connections and more serious problems.
Would any of this apply to a TI-89? I have one with a black column down the right side of the screen. It works otherwise but when I opened it up, it did have parts of an exploder battery. I cleaned it up hoping that was the problem but it didn't fix anything. Thanks!
andrew1227 wrote:
Would any of this apply to a TI-89? I have one with a black column down the right side of the screen. It works otherwise but when I opened it up, it did have parts of an exploder battery. I cleaned it up hoping that was the problem but it didn't fix anything. Thanks!
Sadly, it doesn't apply. That sounds like LCD column ribbon pieces getting unstuck. Part of the LCD displays the image properly, correct?
Yeah, everything is perfect except for the very far right column, blocking any of the answers from displaying
The calculators that always have the black screen of death will not connect to the TI Connect software. Tried several different methods, but the software never picks up a calculator. Thank you.
WoCo2016 wrote:
The calculators that always have the black screen of death will not connect to the TI Connect software. Tried several different methods, but the software never picks up a calculator. Thank you.
That hasn't been my experience at all. As long as [ON] turns it on and [2nd][ON] turns it off, then TI-Connect should be able to connect. If it doesn't, then the calculator has further problems. Try doing a blind OS upgrade from TI-Connect's OS Updater tool?
These calculators turn on automatically when batteries are placed in them, but with a full black screen. [2nd][On] will not turn these units off. The OS download will not work for these. It can't recognize that the calculator is connected.
WoCo2016 wrote:
These calculators turn on automatically when batteries are placed in them, but with a full black screen. [2nd][On] will not turn these units off. The OS download will not work for these. It can't recognize that the calculator is connected.
Sounds like a possible bootcode corruption to me, though I'm not 100% confident on that diagnosis. It definitely sounds like something more serious than a simple LCD problem, though, and probably not worth your time to repair.
I just wanted to thank KermMartian for his excellent documentation of the Ti-83 Plus repair. I fixed mine about a week ago, and- so far!- it's been holding.

Initially, I only repaired ~4 connections that were reading high (kiloohms+, versus single-digit ohms on the rest), and that lasted half an hour. I went back in and did them all after that.

It's always good to repair something like this than abandon it, or throw it out. Thanks, y'all!
Although I'm extremely late on this, I'm glad I was able to help you out! Congratulations on getting your calculator working again.

Also, CVSoft sent me his TI-83 Plus to fix, and I fixed its ribbon cable. I didn't even bother probing it with a multimeter; based on the symptoms, it seemed like a candidate for a full ribbon cable replacement, so that is what I did. You can see the results of the surgery below, along with the note that CVSoft included with the package. Unfortunately, due to my work hours and four hours of commuting a day, I haven't been able to get to a post office to mail it back to him, but I shall do so soon.

Hello!So I ended up managed to salvage a pretty horrendous looking calculator that had blue "acid?" corrosion that seemed like it was caused by some kind of battery leakage. I cleaned it up and basically repaired some traces with my shoddy soldering skills Razz which then the calculator manage to show something up on the screen. Any ideas on what i should do next? Here are the pictures!









  
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