random shutdowns into sleep mode

[luminosity]

On at least half a dozen occasions, my iBook has abruptly gone into sleep mode seconds after I turn it back on from being asleep. I open it up or hit a key, and it fires up, and then just as quickly goes back to sleep.

Any idea what this could be?

 

[matticus008]

Check your system logs for a "Power Management received an emergency overtemp signal. Going to sleep." message. If you see this, download an application like Temperature Monitor and keep an eye on the trackpad sensor (you might set an alarm popup if it ventures below 15C or goes above 55C--that way you might get some warning). If you're having the same problem as dozens of others, it'll be that. Despite what appears to be a recurring issue, Apple has so far refused to acknowledge that they shipped faulty trackpad sensors in early 2005 portables.

First things first, of course--reset PRAM and the PMU and see if that helps.

 

[yg17]

My PowerBook (2nd-to-last rev 15" G4) was narcoleptic and did the same thing as yours did. What happened was the PowerBook's temperature sensors went haywire and were giving insanely high, false readings. As a result, the PB thought it was overheating and went to sleep to cool down. In the logs, I got the exact error Matt mentioned. Sent it out for repair, it came back with a new logic board and bottom casing, and all is good.