Emu XL-7 & MP-7 User's Group

I have an mp7 which is faulty [fails to boot].

Sometimes it shows nothing on the lcd, while at other times it shows '._"

From this I guess that it has completed the first system test but hung on the second. Does anyone have access to a TSM (or other information source) and can describe the tests that are being undertaken with each dot so I can identify what the problem might be? I'm further guessing that the first test is likely to be the SDRAM and that this situation indicates an SDRAM fault.