I was just sorta messing around on my Model 102 just now, transferring a few BASIC programs with dlplus and setting up some RAM images in my REX when suddenly I tried to switch to an older RAM image and the screen came up with a single question mark ? on each line and a ?S on the last line. Power off/on and it showed the same thing. I pulled the batteries and turned off the backup battery and then I got random pixels all over the display. If I hit enter and type "beep" nothing happens either. I pulled the REX out and tried using a power adapter instead of batteries with no luck.
Any ideas? I had it apart a few months ago to replace the NiCad and none of the capacitors looked obviously bad to me.
