I've discovered if I re-seat the TMS9918ANL, the display temporarily clears up, then quickly corrupts again. I found some of these chips for sale on eBay for about $11 apiece (albeit out of Hong Kong).
So, what do you guys think? Do I have the problem pinned down? Is it worth attempting to fix?
And on a related note, is there anything I can do about the missing key caps that doesn't involve looking for another broken TI-99/4a? The caps that are missing are, specifically, 1, I, A, and B.
EDIT: Forgot to mention, the power switch is also missing. I don't mean the physical switch, but the bit that slips over the physical switch so you can flip it on from outside the case.
Edited by jmetal88, Tue Jul 6, 2010 6:55 PM.