Why does it keep rebooting and/or shutting itself off intermittently?
My Macbook Core 2 Duo 13" won't stay on for any significant time anymore. When it does, it seems that the slightest movement, or pressing a key will shut it down or it just shuts down on its own. Or it reboots repetitively after chiming. Or it remains on as it is doing now for the last 30 minutes, long enough to see if it needed firmware update. It's never on long enough to really use it anymore.
When there is no image on the screen, I often can hear the fan or drive running quietly in the background. I can turn it off by powering down. Without the power cord, it will eventually drain the battery if I don't force shut it down.
I have verified that the hard drive is OK by removing it and mounting it externally.
I have been unable to do a hard system reboot (hold down powerbutton until system starts and continue to hold until tone) - no tone, just keeps rebooting.
When it stayed on long enough, I tried to install the firmware 1.1 update. Message was that it didn't need it.
I have tried removing one RAM card at a time ( it has 1GB + 512Mb). Haven't really noticed any change.
Sudden motion sensor is shown as enabled. Any idead?