right, i will start with the spec:
Gigabyte GA-73PVM-S2H motherboard
ATI HD4650 512mb graphics card
4GB Ram
Intel E8400 (not overclocked)
80GB hard drive
Cheapish 650W PSU

right, here is what happened. I decided to try the beta version of windows 7. I replaced my current xp, and once installed, deleted the windows.old file. I then downloaded a game (rigs of rods 0.36) and whilst playing, I got a BSOD (something about a physical memory dump). Since this happened i have been unable to boot windows 7 as it froze during the boot (it sometimes froze before booting 7 and even in the bios).

I then put windows Xp back on and it still froze randomly (anywhere between a few econds and 20 minutes). I then flashed the BIOS with the most current one, this stopped the freezing. I also took out the graphics card and used the intergrated piece of crap and it seemed fine.

I had already installed all of the drivers. Now, my computer doesnt freeze, but is shuts itself down instantly (as in, just cuts out), this can happen anywhere between 10 seconds and 2 hours after switching on and i have no idea what to do next. Any help?

Thanks in advance.

Quote from anbiddulph :

Cheapish 650W PSU

Already tried with a different one?

Quote from R.Kolz :

Already tried with a different one?

no i havent, but i will be taking it back to the shop i got t from to check i its the problem

Virus w/ rigs of rods is my guess.

Quote from MijnWraak :

Virus w/ rigs of rods is my guess.

Virus can't damage your hardware (unless it will reflash bios )

My best guess is the PSU, if the PC is shutting off on its own, maybe check if some lights on the computer are still on. (ie. The lights at the back if there are any)

My second guess would be the motherboard, maybe a power cord connection is loose, causing the instant shutdown.

Check your CPU temps. I knocked off my heatsink a while ago, so it still looked on but wasn't clipped on two of the prongs. It'd shut down and reboot randomly to protect the CPU.

Also, if you can open your PC case, try removing everything from your motherboard and reconnecting again (except CPU). I solved 90% of problems this way.

Quote from S14 DRIFT :

Check your CPU temps. I knocked off my heatsink a while ago, so it still looked on but wasn't clipped on two of the prongs. It'd shut down and reboot randomly to protect the CPU.

clever man, i checked this with coretemp, which told me my cpu was at 60-70 degrees at idle! turns out my heatsink was loose :P. down to about 40 at idle now with the fan set to full all the time, it used to be at 45 at full load. why is it warmer?

edit: used a cpu stress test thing, and the tempurature rose quickly, i abandoned it at 65 degrees, but it was still getting hotter

Edit: not it wont boot at all, i cant even get to BIOS

Yup sounds like it.. check your CPU cooler. Open up the case and check the cooler. Make sure it's on properly.

now its stopped booting, the CPU cooler isn't loose, nothing is loose, I have tried everything, one stick of RAM, with graphics card, without graphics card, etc. I don't even get anything to the screen. no bios, no nothing, it just omes up with the 'pc entering power saving mode' ie. nothing is sent to the screen. I have had the PSU checked, it isn't that. any, and i mean, any ideas?

Tried doing this?

Quote :

Also, if you can open your PC case, try removing everything from your motherboard and reconnecting again (except CPU). I solved 90% of problems this way.

I hate to say it but it could be a cooked CPU???

I noticed you mentioned it running at 60-70 on idle before you found the loose heatsink.

It doesnt very long to @*(^ a processor up if its overheating, or has been overheated in the past, the damage can already be done, and with these idle temps, just think how hot it must have been getting under load!!!

I really hope it isnt that but it dont sound good if you cant even get to bios.

Quote from danthebangerboy :

I hate to say it but it could be a cooked CPU???

I noticed you mentioned it running at 60-70 on idle before you found the loose heatsink.

It doesnt very long to @*(^ a processor up if its overheating, or has been overheated in the past, the damage can already be done, and with these idle temps, just think how hot it must have been getting under load!!!

I really hope it isnt that but it dont sound good if you cant even get to bios.

I doubt it, I have a Q6600 that regularly would idle at 85 degrees according to Bios many times before I realised what was the problem. It's working fine now idling at 40 and load at 48 or so. You can access the BIOS without a CPU. If the CPU was broken it would say that it's "unworkable" or someshit, like it said to me when I stuck it in the wrong way.. (that's what she said!)

Actually you can't access the BIOS without the CPU...

Quote from Jakg :

Actually you can't access the BIOS without the CPU...

Wierd, I could.

I don't think you can get into BIOS without at least CPU, RAM and GPU. Mine just gives beep codes if I start it without the CPU...

Also, how did you manage to stick a Q6600 on the wrong way...They have a corner cut off for idiot-proof installation

I know, I didn't realise.. well, I did, but then for some reason I must have been an idiot and put it in the wrong way. But other than that it was a very idiot proof build, thankfully I had to take everything out to change the case at the same time so it was much easier.. but building PC's are piss anyway nowadays. The first one is hard then after that it's the same but with different names on the things.

right, new discovery, next to no power is going to the fans (CPU and graphics card), you can stop the CPU fan and it wont start again, and the graphics fan just doesnt turn, is there something wrong with my motherboard?

If you stop the fan and it won't start again it could be your mobo reducing the power to the fans to slow them down - mine does this to my (now removed) Zalman Reserator cooler, and in some situations while it has enough power to move, if you stop it it won't start again.

As it is - this shouldn't be an issue as long as you aren't ****ing around with a PC that's on, they should just spin up on bootup.

Try disabling any noise control features on your mobo?

Quote from Jakg :

If you stop the fan and it won't start again it could be your mobo reducing the power to the fans to slow them down - mine does this to my (now removed) Zalman Reserator cooler, and in some situations while it has enough power to move, if you stop it it won't start again.

As it is - this shouldn't be an issue as long as you aren't ****ing around with a PC that's on, they should just spin up on bootup.

Try disabling any noise control features on your mobo?

i cant get to BIOS, you switch it on and nothing comes on the screen

Have you tried resetting the CMOS?

Quote from samforey12345 :

Have you tried resetting the CMOS?

by taking the battery out? yes

Quote from anbiddulph :

by taking the battery out? yes

On most (all?) boards you have to remove the CMOS battery and move a jumper to clear the CMOS. Check your board's manual to see if a jumper is mentioned.

Quote from amp88 :

On most (all?) boards you have to remove the CMOS battery and move a jumper to clear the CMOS. Check your board's manual to see if a jumper is mentioned.

no mention of jumpers, but this time i shorted out the holder (like it says in the manual)