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Thunderbird8

macrumors regular
Original poster
Dec 11, 2007
217
0
UK
What it says really, I have a 2x2.8 quad Xeon Mac Pro (spring 2008) and have just encountered a problem over the last few days where the machine restarts completely un-prompted and for no apparent reason.

This can happen at any time. Other times the screen goes blank and the machine still seems to be 'on' but then needs to be shut down by holding the power key down.

Have just reset PRAM to type this and so far so good, it hasn't shut down yet....
 
Sometimes it will fix issues with the HW, yes. Sometime pressing the onboard SMC button can do it as well.
 
No, reset PRAM yesterday and it stayed on all day, woke it up this morning and it self-rebooted after about 10 minutes. Reset PRAM again and so far so good today.
 
No, reset PRAM yesterday and it stayed on all day, woke it up this morning and it self-rebooted after about 10 minutes. Reset PRAM again and so far so good today.

Reset the SMC. As the links I posted earlier show, PRAM/NVRAM has nothing to do with your issue. The only reason it appears to help temporarily is the reboot that you do in the process of resetting NVRAM.
 
Have reset both PRAM and SMC however this morning the same problem re-occurred. I reset the SMC again however any more ideas gratefully received...
 
Take everything temporarily out of the logins and startupitems and clean boot for a while and see if that helps. Is so put back a few at a time till you find the trouble. You might try reinstalling the OS and the OS updates on top of your existing install. Other than that it sounds a bit like a hardware problem. The easiest thing to try would be cloning your drive over to a different os drive to test that.

Also you might want to boot into single user mode and run some disk repair commands. http://support.apple.com/kb/TS1417
 
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