You really shouldn't be doing this for your friend. He should be doing this for himself. You seem to be a good friend but don't let your friends walk over you, okay?
Secondly I can't even diagnose anything without a log file anyway, we try to warn people every single time they view the forums, every single time they even make a post that they should give a log file if they have a problem, so it's just rather difficult to do anything to help if we don't have that unfortunately. Especially in this case where I can't see the specific error code which may be causing the black screen