I'm having a worrisome problem with my MDD dual 1ghz g4. It will sometimes turn off when in sleep mode. When I try to boot it back up, it comes on and chimes and I can hear the HDD spin up, but then it will just turn off. Usually after about 3 or 4 attempts it will boot up just fine. I thought it might be the battery on the logic board, since the clock would re-set every time the machine was powered down, so I replaced it. That fixed the clock issue, but the machine is still turning off and taking several attempts to start back up. I have no idea what is causing this. One thing I do know is that this house is pretty old and the wiring seems iffy. I have a battery backup on another machine and sometimes it will start beeping like it's lost power, but it's still plugged in and the light indicating that it's receiving power is on, so I think sometimes the power from the wall fluctuates. This might explain the MDD spontaneously shutting off, but does it explain the difficulty restarting? BTW, I searched the forums to see if anyone had asked this question, but found no threads, so my apologies if this is a repost.