Computer Will Not Stay On...Power Switch??

moosey

Golden Member
Apr 18, 2001
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My computer shut off on me and now I can't get it to stay on. Sometime it will go on but only for a few seconds and I can't even go into windows because it shuts off. My power supply is 400watt and I was able to check the voltages in BIOS and they seemed ok. So I think its the power switch or the wires coming off of it from my case or the connector on the motherboard. Any Help?
 

chocoruacal

Golden Member
Nov 12, 2002
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The power switch is a momentary switch. Its really not possible for it to turn itself off unless you have a poltergeist or something. Most likely you have a system component failing...power supply, RAM, motherboard, in that order. Could also be a heat issue...check that your CPU fan doesn't look like a wookie.
 

beatle

Diamond Member
Apr 2, 2001
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It could be the power switch if it's binding up. Try this: unplug the power switch connector from your motherboard, then short the 2 pins that it was plugged into with a pair of needle nose pliers or even a paperclip. This will power the computer on. If it doesn't crash, your switch is bad. If it does crash, the problem lies elsewhere.

Re: voltages, are you able to let the computer idle in bios for an extended period of time? If so, it could be that the extra power needed to get the machine into Windows causes one or more of your rails to drop and then the machine reboots.
 

moosey

Golden Member
Apr 18, 2001
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What if shorting it does not turn it on. I'll try again but I could not get that to work yesterday.
 

mechBgon

Super Moderator<br>Elite Member
Oct 31, 1999
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If the power switch is internally stuck in the "pushed" position, it will have the same effect as if a person were holding the button down. The motherboard interprets a held-down power button as a signal to shut down. But if this is what's happening, then 1) beatle's test will reveal it, and 2) the motherboard would power up immediately when the power supply were plugged into the wall, then power down after about five seconds.

The other likely possibility is that the motherboard is getting an emergency shutdown command from the CPU. If the CPU is an AMD, the reason it's overheating that fast is going to be a lack of thermal transfer from the CPU to the heatsink. Lack of thermal transfer is usually caused by a heatsink that is on backwards instead of the right way, but sometimes by a person using a shim, or forgetting to use thermal grease, or forgetting to take the coverslip off their thermal patch.

Special cases: the clip's in the heatsink backwards (common with ThermalTake Volcano 7+, which comes disassembled), or a heatsink that has some room to move back & forth on its clip and it's too close to the raised, solid-plastic end of the CPU socket and has ridden up on it (common with Thermalright SK-7 and SLK-800/A).