Okay, I've been having some complicated troubles with my powerbook the past few days. Basically, it's been either shutting down completely OR going to sleep during start-up (either during the "starting OS X", or shortly after reaching the desktop). I managed to restart it using the reinstall disk, and then restarting using the powerbook (that only worked out once in a while, often it shut down then too!). I managed to read the system log, and it read something like "emergency overtemp, going to sleep" (this was from a TOTALLY cold start). Called AppleCare Japan, and they suggested taking out the battery (and power cable, obviously) and hitting the power button for 5 seconds. So, I guess, to reset the system or something? (sorry, I'm an amateur when it comes to this stuff!) That worked fine yesterday, but today when I tried to power up the computer it immediately went to sleep again! After a lot of restarts, I managed to get it working again. A friend of mine suggested that maybe it's a short circuit or something, and needs a new motherboard (yikes! ). Anyway, I decided to carry it home from work today in sleep mode, hoping to get online and solve the problem. Then, when I tried to start up again (from sleep mode) it was sluggish and I thought it was the same old thing over again (though it did manage to wake up after 10-15 seconds or so). ANY help or advice would be GREATLY appreciated! Should I bring it into the Apple store for repairs or what? Thanks!