"Fun" with the TI99-4A

[atrax27407]

I have spent the past two days ("off and on") working on a couple of TI consoles with keyboard problems. Both had a sticking key. It wasn't the mechanism itself that was the problem but rather the keycap. When I removed the keycap, the key worked fine but it appears that the keycap was binding either on the case or maybe the adjacent key causing it to stick (something to check if you have keyboard issues). I tried several other keycaps (I have a large bag of spares of various designs) but none of them solved the problem even though they appeared to be identical.

 

So, into the closet I went and pulled out a couple of non-functioning consoles and swapped out the keyboards for those in the two consoles with problems - one an AVPC-modified console that I call "Black Max" because the aluminum trim has fallen off the bottom half of the console and the other one is my stock console that I use daily. Both replacement keyboards were non-Mitsumi keyboards (from Korea) that I installed and the connector cable was MUCH more substantial than the usual wimpy ribbon cable on most of the keyboards around. All in all, it was a fairly quick and easy repair.    

[Ed in SoDak]

Good to have spares for a fairly easy swapout. I've had to resolder switch contacts to the underside of the PCB a few times. Maybe that allows the switch to move enough to bind the keycap? When I get a sticky key, usually I have to dig out some crumbs and grunge under/around the keycaps on mine.

-Ed

[HOME AUTOMATION]

Looks like you've given new meaning to playing MunchMan!