Pretty much. Normally, the LCD has a few layers bonded together, sealing each other so everything stays where it should be. If there's a spot that comes unbonded or a tiny fracture opens in one layer, the liquid crystal leaks into the void or crack and deforms, making the dark blob. I've heard about "squeezing" the leaked blob towards one edge, but I've had no luck with this approach. It's particularly annoying, as it spreads, is difficult if not impossible to fix, and ruins many a good calculator.

I replaced the ribbon cable on a 83+ SE nearly a year ago; I've wanted to write up a blog post describing the typical symptoms and walking through the repair, but haven't. What I do have and can easily share right now though is a time-lapse video of the soldering:



The wire I used and general soldering job isn't particularly good, but it did work out in the end. If you're paying attention to connecting the two ends together, I had to attach one wire further up on the LCD board after I lifted the pad, so I had to remove soldermask elsewhere on that trace so I could tack the wire on.

Hi y'all! Sorry to resurrect this ancient post but I recently got the black screen symptom and after checking the cable on the 83P, I realized that some pins had around 38mO of resistance which was probably causing this issue. After soldering too hot and lifting three pads and locating other vias/pads I could use for them, I successfully connected all of them. I just wasn't able to test one pin (fifth one from the left, via L6 on the main board) because the trace just vanishes behind the LCD on the LCD board. All the others I could track down two other spots which connect and thus ensuring a good connection. When turning it on though, it seems like you can see the update cycles of the LCD by pulsing full black and white screens. When changing the contrast or dong anything really, it flashes quickly as if it were updating it accordingly. I'm guessing that this is the best place I could ask to get my ancient calc running again!

Thank you all in advance!

P.S.: Yes, it turns on and off, so it would probably show up in TI-Link as well. Yes, it worked perfectly before just going black. No, I didn't short any pins.

Welcome! And this is still a pretty active topic, at least by frequency of this occurring on people's calculators if not frequency of posts. Can you share any images? Did you try screenshotting it in TI-Connect?

Here are some images:
https://upload.skyslycer.de/t83p_vid2.mp4 (the fast flickering is only from the camera, the slow on and offs of the display are the thing humans actually see)
https://upload.skyslycer.de/t83p_pic.jpg (solder joints are very far from perfect, I know)

Surprisingly there are no shorts, I have triple checked everything. It's just that one pin that I can't test, I have tried resoldering that pin to no avail. Any ideas?

And no, I have not connected it to Ti-Link, as I'm mostly on Linux and TILP is a PITA on my current distro. But just by the functionality of the calc there should be no problem with the thing itself. Anything you need specifically?

Try cleaning the solder joints. I had problems with used flux creating conductive paths through adjacent pins.

I have cleaned them with alcohol and they look nice now. Same issue though. And I doubt it was the flux since I still couldn't detect shorts between the pins. Back to the drawing board I guess

Hi, sorry to bump this post but I'd really appreciate some more suggestions Any other ideas?