I have this 800XL which works perfectly in stock configuration (or at least it does when no PBI device is connected). My first attempt to mod this computer was with a U1MB and it failed. The device worked somehow but there was an issue with the screen corruption when I entered U1MB setup menu. I never could figure out what was wrong with it and instead installed the U1MB to my 130XE, end of frustration. Lately I wanted to try my IDE Plus 2 with the same 800XL. When I connect the device the 800XL comes up with a blank screen, no other activity at all. When I disconnect it 800XL works as usual. It seems to me there is a PBI issue with this particular 800XL as IDE Plus 2 works flawlessly with my 600XL and 130XE.
What do you guys suggest that I should check with this 800XL to find out what could be wrong.