I've just recently(as in over the last two days) started having a problem with my Powermac G4 Digital Audio. I have made no hardware changes to the computer in this time frame. Basically, the computer will randomly power off when I'm using it. Sometimes it will happen during startup, sometimes within a few minutes of startup, and at other times I can get several hours of use out of the computer. Sometimes, when it powers down, I can restart it immediately. At other times, it will be a little while before I can restart it. I'm guessing this may be a sign of a PSU on its way out-any thoughts on how likely this is? In addition, now whenever I startup the computer I get a single beep accompanied by the power LED flashing. As per Apple, it looks like this is indicating a POST problem. http://support.apple.com/kb/ht1547 However none of these seem applicable. Once the LED stops flashing, I will then hear the start-up chime and the computer will boot as normal. I have not counted the number of flashes(I didn't realize that was significant until finding that page just a few moments ago) but will do so on my next start-up. In the mean time, does anyone have any suggestion as to what could be causing the problem? I have reset the PMU, and in addition have installed a new clock battery.