SG Broadband Community

I have self built vista computer that is a few years old. For a few months it has been just shutting off at seemingly random times - not a warning and a reboot - but just shutting off with no warning, like someone pulled the plug. I just sort of lived with it for a few months trying to figure out what was going on. Last week it started telling me that windows had detected a hard drive problem at start up so I figured that was the problem and replaced the hard drive. I was still installing drivers and it just shut off on its own again (the hard drive was obviously not the problem). A bit later I was instlling the drivers for the video card and it shut of and it will not reboot now at all. I reset the bios but that did not change anything. It boots past the mother board screen and gets to the reboot selection screen but no matter which type I choose (not even safe mode) in about 5 seconds it just reboots and just comes around again. Anybody have any idea what is going on before I just start randomly replacing items?

A few things that wasn't suggested in general turn off all power saving options in the bios and also in windows control panel. Don't forget most network cards to do have power on off fuction so check control panel network/sharing your connection then configure.
In the bios in the boot order screen if you are using more than one drive try changing the order of the booting for the hard drives. It sounds crazy but my one board does the same thing random reboot untill i change the boot order of the hard drive.

Clean the computer out with compressed air also check that everything is seculry seated ram/vid card any type of card.


If the power strip is older replace it ,if the power supply is older replace it.

Like Mccoffee said clean out the dust with compressed air, don't forget the power supply. Once thats done I would re-seat your RAM and any add-in cards like Video, network and sound. The hard drive may not have been bad, it may have just got some corrupted files from the shutdowns. If you haven't chucked it out yet, test it to see if it's still good. You can get free utilities from the drive makers site for that. If you PC still won't post disconnect anything you don't absolutely have to have for it to boot up. Once you get it to post go into the BIOS and have a look at the temps. If I had to guess I'd say it's ether overheating of the power supply is failing.

Some listing of the hardware components might help..
Motherboard..does it have the latest BIOS?
Memory, is it certified compatible RAM with this motherboard?
Power Supply...a decent one?
Speaking of memory, is it non-standard memory that requires above the standard 1.9volts? Requiring you to bump up the voltage in the BIOS.
Heat Sink Fan properly mounted with a thermal pad?

I'd go into the BIOS, reset to factory defaults. And then go from there.

System files probably corrupted by now from all the sudden reboots, I'd grab what data you can to backup..and then start fresh...blow away the existing system partition, give it a full format, reinstall.

OK, I got it to boot again. I did a "fix system" using the windows installation disk - that is the first time I have actually had that work.

Now about the random powering off. While it often turns off for no apparent reason I can cause a shutdown by taxing the system - say by rendering a video or burning a DVD - anything that uses a lot of resources. Someone talked about overheating so I took the cover off and it does seem to be better. There is a duct to the fan on the chip and a case fan but perhaps I need to look at that closer.

My question is ... will a camputer just trun off with no warning when the chip overheats or do I have to look at the power supply first?

Overheating can cause random sudden reboots, locking up, blue screens, etc. The heat sink on the processor usually has tightly packed fins...and dust can accumulate on them...what I call a lint blanket. Sort of prevents the air from properly passing across the fins, even when the heat sink has a fan on top of it.

If the heat sink has a shroud over it, remove the shroud...get a can of compressed air.

Yes the PC can suddenly shut down if the processor overheats. There should be a settings in the BIOS to shut the PC down when the temperature of the processor reaches that set value. It's default value is usually lower than the actual maximum core temp for the processor so your PC would normally shut down before the processor gets damaged by excessive heat. You can change the setting but I wouldn't. Like YeOldeStonecat said take the dryer duct off and clean out the lint trap.