G4 Quicksilver shuts down on going to sleep

Hi. I'm having problems with my mac shutting down immediately when I put it to sleep. The light on both the computer and the monitor go out, the fan dies and the computer won't wake again no matter what I do.

To compound the problem the computer won't boot up again. I hit the power on button, I hear the start-up sound and the fan kicks in, but then everything dies. Usually I have to try this 3-4 times before it eventually boots. It seems that if I wait a few minutes then it boots straight away.

I have replaced the backup battery, reset the PRAM and NVRAM, and the PMU. I've run OnyX and verified permissions, etc. I've also disconnected all peripheries and uninstalled the soundcard software. Basically nothing has helped.

Stats: G4 Quicksilver, OS 10.3.9

Can anyone help?

Many thanks,
Robin

Just a bit more info. Booting in safe mode didn't help. Also when I shut down the computer and then try to boot it up again immediately I get the same problem - it dies after a couple of seconds. Then if I wait a minute or 2 it boots fine.

G4 shuts down when i tell it to sleep....

Did you ever figure out what was wrong with your computer?

I'm having the same issues with my G4 osx 10.4.11 (mirror door). There have been two instances when I've had an issue getting it to start up. The button on the tower lights up for a split second and then off it goes, but the machine doesn't start. I try using the monitor as a power and I hear the fan start, but it doesn't turn on. i have to wait several seconds and then try the monitor again. Holding down the power the fan starts and I hear a tone and then the apple start up noise and then the computer turns on.

I know people talk of reseeding and moving things around, but I don't know what any of that is. I have a general idea, but I'm not technically inclined. But I've come across many threads about this same issue and there seems to be no solution.

I'm worried that one day my mac won't turn on.

That could be a dodgy Lithium Ion battery. Try replacing the battery on the motherboard (its in a square plastic housing), its a cheap part

The lights turns on and doesn't start issue was solved on my old G4 by replacing this cheap part