Fixing 800 video--where to look after GTIA?

[1050]

Yep, too easy so that's not it. I'm suspicious of the

ROM eproms now. The old silicon wasn't all that great

back then and large improvements were made since then.

 

Sam's Photofact at atarimania might help you with

some scope compares too.

http://www.atarimania.com/documents-atari-400-800-xl-xe-technical-documents_3_8.html

 

RESET line not high enough? Any address activity?

There has got to be some clue somewhere I would

tend to think, best of luck with it. Get back and

let us know - the next guy is already pulling his

hair out.

[vputz]

Haha... but in this case, your ROM instinct was right. We got a whole working 800 (underpackaged, in "media mail", with most of the keys blasted off the keyboard, but they went back on just fine) swapped the personality board and it popped right up. Not sure which component on the personality board, but that was evidently the bugger. Always the last place you look.

 

Thanks for the pointer to Sam's! We had compared the scope traces to the pics in the 800 field service manual and they seemed to hold up, but this seems like a good resource; I'll check it out. Although I'm probably going to be tapped for some 8-bit retro entertainment for the evening now that it's back up and running