If replacing the MB is done then what does that leave? Memory? Power Unit? maybe that little power switch unite; these were common problems on earlier G4 duals. Swap memory with the good MDD. Bad cable? roger On Aug 14, 2005, at 3:04 PM, Jay E. Krauss, Jr. wrote: > I have two MDD G4s, both maxed out with four hard drives and 2 > GB RAM and running OS X 10.4.2. One gives me no problems; the other > has developed the nasty habit of suddenly turning itself off. I've > taken it to an Apple authorized service center once and a logic > board was replaced. This solved the problem for about a month, now > it is beginning to happen again. Tech Tool Pro detects no problems > with any of its tests. The hard drives check out with both Disk > Warrior and Disk Genius. I've hooked it to a UPS to eliminate > possible electrical fluctuations. The CPU temperature stays under > 59° C and the hard drive temperatures 37-44°C (similar to the > functioning unit). > Has anyone else run into this problem, and if so, was there a > solution found? > _______________________________________________