System Shuts Down!

My G5 Quad Core, which I've had for a couple of months now, has recently taken to shutting down completely without warning - sometimes only a few seconds into start-up. I have a Blackmagic SP PCIe card, and just added 2 gigs of memory.

Any ideas what might be causing this? Very infuriating, expecially on a deadline...

Thanks!

And Add To That a G-Raid that suddenly disconnects from the system without warning....

I'm not sure if all this is related, but I don't want to suffer a complete system melt-dwon at this point...

Disconnect all non-essential peripherals from the computer -- including FireWire, USB, networking. Also make sure the memory units are plugged in securely. Run the computer and see if it still behaves the same way.

Could be a problem with the PMU (Power Management Unit) that controls turning on and off the power supply of the G5. You do havve a one year warranty and you DID buy Apple Care, didn't you?

<<<Also make sure the memory units are plugged in securely. >>>

I don't entirely agree. Put the original memory back in. Pull your stuff out. Be sure to lean on something grounded to avoid static electric damage. I think the book may have good instructions on this.

<<<Could be a problem with the PMU (Power Management Unit)>>>

Entirely possible. So to reduce the machine to the smallest possible unit, pull the memory first. bad, ratty, or improperly installed third source memory is far more likely to cause problems than a broken PMU.

Koz

Thanks, I'll explore these suggestions and report back......

As for the G-Raid, call their tech support and they will replace it for you. They had a batch of Raids that had a bad chip in them. Your data will be fine. They sent me a replacement, I copied my data to it, then sent the bad one back to them.

I'm still having this problem - I've removed all memory (down to the original 512), and the system still shuts down. I might go for several hours without a problem before the shutdown, or it might happen on start-up, or after a few minutes. No lights, nothing - just an accelerated fan and a complete shut down. At the moment, I can't get it to start up completely. Fans start, I hear the start-up tone, and the system shuts down.

I brought it once to my local Apple Store, which plugged it in for a couple of hours (of course the system didn't shut down then). Their only theory was bad memory, but I've proved that wrong.

Anyone have any idea what this sounds like? I know I'll have to bring it in, but I'd like to hear from anyone who knows about this issue. Again, I have a G5 Quad.