Did you say that it only does this when you have some USB device plugged in? I deleted the original message because I didn't think I had any idea what was wrong. If it only happens with that USB device plugged in, then I think your logic board is probably okay. What if you unplug everything else except that one device (and your mouse and keyboard)? Do you have any non-essential PCI cards that you can take out to see if that changes the behavior? Try taking out all but one RAM card, then try moving that RAM to other slots and see if that helps. That should help you find out if you have a bad card or a bad slot. -- Rich > -----Original Message----- > From: Roxylee > > Re: The problem with my G4 QS shutting down with the LE plugged in: > It shuts down a few seconds after the Gray Apple logo comes > up. I tried it twice just now, same deal.