pc shuts down suddenly after turning on

[dmaloof]

This happened suddenly in past 4 days. i turned the pc on and then it shut off. repeated same thing. it even did it in safe mode. Sometimes I would get in to the desktop and after 10 minutes it would shut down. Same if I put it in sleep mode and wait several hours to find it shut down on its own. Any idea what could cause this. i have asvast anti-virus and adaware running in background and ran scans while i could keep the machine on and nothign showed. It is a windows 7 OS.

[Pen32Win]

Sounds like a power supply to me!!!! Had the same thing happen to me..... If you bump the tower does it reboot then?

Try blowing out your P/S first before replacing it.

[dmaloof]

hmm, did not try bump the tower. I unplugged and replugged stuff. the fan is fine. It's an HP pavilion refurbished.

[Robert John]

Yes I had this problem. I vacummed out in side carefully. tested the seating of components carefully.Don't for get to touch something metal that is earthed to get rid of you static before touch any components.My computer is still hanging on by replaceing this and that secondhand parts.
Yes I bumped my my desktop with a size8,I think they call this reboot.LOL. It sounds like a powersupply or overheating because of dust.
Robert John.

[Fibber]

I agree with the dust factor. I was having some problems with my Dell a Radeon x850. I found that inside the fan vents the heat shunt fins were clogged with dust bunnies that had been forced in there. Clearde them out, along with the rest of the insides, and everything became good again.

[dmaloof]

Hi, thx for advice. i have another pc that is hp but vista os. i have 2 desktops at home so if one goes or acts up. i use the other one. This vista had a prob too in that it would not boot to window and stayed at hp invent screen. So i took apart reseated the RAM modules and cleared dust away from that area and now it works. The windows 7 pc I took to the shop and probablew should have waited and tried to reseat or clean. Cost me 59 bucks and wont know till today. But I shd have waited to try reseat or dust clean, unless it needs a new power supply. they're both HP pavilions. But the one that was shutting down suddenly was something I never faced before.

[nomad13]

Most CPUs have thermal protection built in; when they get too hot, the computer will shut down without warning. This can happen when the CPU cooler is clogged with dust or the CPU cooling fan is not working. Take the side panel off the computer case, power up the computer and make sure the CPU fan is spinning. If not, your computer is going to shut itself off pretty quickly to prevent the CPU from frying. It's not very common, but sometimes when a computer is banged around, the CPU and/or the CPU cooler can be unseated. Also, if cheap thermal paste between the CPU and CPU cooler is used, it can wear out, causing the CPU to overheat.
If you have memory(RAM) problems, usually you get beeping before the computer boots up. If you have so much dust in your computer that the memory chips are overheating, you need to clean it out way more often.
It could be the power supply as well. Usually, not always, PSU's will start acting up before they go out completely; monitors will go black, programs will crash without warning, things that weren't happening before.
I would encourage everyone to learn enough to fix their own computer. It's not really that hard and kind of fun.
Hope you get your problems straightened out.

[dmaloof]

Hi, thx for replies. i got it back from shop today and they said it was due to power settings on the usb ports cauisng the pc to shut down suddenly. . I am happy it works but had to dish 89 bucks out for the testing and diagnostics and service.