I recently got a TI-83 Plus with ~4 lines on the display that are blank:



I'm not able to get them to light up when holding DEL and inserting the last battery, and I've confirmed all of the traces on the white ribbon cable have continuity:



There's no physical damage to the screen, so does this look more like an issue with the black ribbon cable instead?

I've searched the forums, and found some great resources on isolating the white ribbon cable, but not too much in regards to the black ribbon cable.

Thank you all in advance!

Yes, this looks like a ribbon cable issue, however, I honestly think you risk damaging it more for a small inconvenience, I would advise against trying to repair it. Heat seal ribbon cables aren't meant to be repaired and doing so is quite tricky.
What's the factory and HW rev on the back? I might need a picture of the whole PCB, looks like pre-2004. We're still missing a handful of TI-83 Plus PCB pics.

Thank you for taking a look!

Is there a way in software to just not use the last 4-6 rows of the display?

I tried to find the factory and HW rev on the back, but didn't see anything that I recognize as those. Could you let me know where that's printed, or what to look for specifically?

I'm happy to take any photos you need — I have a 20x microscope if that helps.

I can't think of an easy way to do it, the OS expects the whole lcd to be there...
As for the revisions, its right here:



The end of the serial number is N-0507T in this example, meaning it was made by Nam Tai in China in May 2007 and it is HW revision T.

The OS is not really written to have resizeable screens (unless you count HORIZ split, but I'll get to that later). It is, however, possible to shift the entire LCD up by any number of pixels if you just quickly want to see what is hidden behind those rows using the hexcode 3EXXD310C9 (where XX is 40-7F, 40 being the default and each higher number being one pixel more scrolled up). Someone could probably make this into a getkey hook so you can press a key to briefly show the hidden rows.

For example, run 3E60D310C9 to display the bottom half of the screen in the top half, and the top half in the bottom half. You can for example have two programs, one with AsmPrgm3E60D310C9, and another one with AsmPrgm3E40D310C9, and call either one to choose which rows are hidden.

Or, and this seems like the easiest solution to make it kinda usable, you could just run 3E60D310C9 once and switch to HORIZ split mode, so the upper half of the screen is usable as a homescreen.

Taking a look, I'm seeing I-0299A.

I'm assuming that means this is from February 1999 (wow!), is there a resource to find what the "I" means?



Thank you for this!

I searched the forums for how to run hex code, and came across this:

https://wikiti.brandonw.net/index.php?title=83Plus:Ports:10#Write_Values

Would that be the best resource for this specifically? I'm assuming I'll also need a cable to connect the TI-83 Plus to a computer, right?

On that page you can see the commands you can send to the LCD controller in ASM. I already told you the commands though, 40-7F. The 3EXXD310C9 hexcode will send the command XX to the LCD controller. To run a hexcode, open a new program in the editor, and insert AsmPrgm[hexcode] (AsmPrgm can be found in the Catalog, a little under Asm( ). Then, run the program with Asm(prgm[name].

If you want it in a screen capture, here:

Yep, "I" stands for Inventec in Taiwan. You've got one of the more common revisions so there's no need to document it
There might be a more official list of factories somewhere but there aren't that many so here is a quick list:

• S - Inventec Shanghai (China)
  
• P - Inventec Pudong (China)
  
• I - Inventec Taiwan (not China except if the Chinese government is watching, in which case, China.)
  
• N - Nam Tai (China)
  
• L - Kinpo Philippines
  
• K - Kinpo China
  
• M - unknown? Malaysia

I quite like the idea of switching to Horiz mode and swapping the lower and upper halves, pretty clever.

Thank you both for taking a look!

I have everything put back together, and have the program working to flip the display.