I've been working on fixing up my Atari 1200xl. Diagnosed it to a bad CPU and possible ANTIC. I ordered both chips from myatari on ebay. After a back and forth, I got the chips in. Popped in the new CPU and voila, my Atari 1200xl was back up and running. Not so fast....
While it was working great with the Pole Position cartridge, after a few more boots and hooking up the Fujinet, I started to get some weird graphic artifacts and the Fujinet would lock up on connecting to WiFi. So, I go and replace the ANTIC chip. Success! I am able to boot into Fujinet and actually load some files. Not so fast....
After booting into some games, watched a demo, I started to get this funkiness. When finished with the current program, I would power off the Atari 1200xl, power it back on, and just a black screen. Nothing, no Fujinet boot. Power cycle a few more times, still nothing. Removed the Fujinet. Power cycle, still black screen. Pop in the Pole Position cartridge, and bam, back up and running. So I go back and insert the Fujinet, it powers up fine. So.. let's load up some SALT or tests. They work and all tests are passed. Power cycle to go back to Fujinet and Not so fast.. black screen again. If I remove the Fujinet, pop in Pole Position it comes back.
What could it possibly be at this point? Is there a delay-line reset chip I need to look at?
Suggestions what to tackle next?
Oh, and I'm going to have to do the mylar fix on the keyboard too.