computer reboots

[mike13]

I am working on a friends older computer P4. Systemax Venture 8524. When I first got the computer it kept booting to the page where you have choices like SAFE MODE, SAFE MODE WITH NETWORK, LAST KNOWN GOOD START. START WINDOWS NORMALLY etc. No matter what I clicked on, the same page eventually came back. A few scarce times I got this message : A PROBLEM HAS BEEN DETECTED AND WINDOWS HAS BEEN SHUT DOWN TO PREVENT DAMAGE TO THIS COMPUTER. and then PAGE_FAULT_IN_NONPAGED_AREA.

I suspected viruses, so I was able to boot to the CD rom and I loaded Wipe Drive Pro, and wiped the hard drive. I then installed XP Pro, with the usual full format at the beginning. BUT, now

the computer clicks off for a second, and then restarts. It seems to do it mostly after the computer has been off for several hours. At first startup it might take three attempts to completely get to the desktop. After the computer is on for an hour or so, the temporary shutdowns are much less frequent, maybe happening once every half hour or so. I have disconnected the DVD unit, the floppy, and alternately removed each memory stick, to no avail.

I turned off the screensaver, and power savings options. I also disabeled the auto reboot after a crash etc. hoping that I would see a error message, but nothing. All I get is a black screen for a second, and then the computer reboots. This occurs very fast, the fans do not even slow down during this quick off and on. Since these shutdowns become less frequent as the computer warms up, can I eliminate the PSU as the problem, or could it still be the power supply. ?? Any suggestions ?? Thanks, Mike

[CoffeeFiend]

Since these shutdowns become less frequent as the computer warms up, can I eliminate the PSU as the problem, or could it still be the power supply. ?? Any suggestions ?? Thanks, Mike

That is no reason to rule out the power supply (more like the inverse). It's fairly likely that you have a bad PSU or a bad motherboard (bad caps are definitely a possibility in both).

If you can, try to swap the PSU with another one (if you got a spare on hand) and have a good look at the caps around the CPU at the same time.

It would help knowing more about the actual hardware as google returns no relevant returns for that brand/model.

[puntoMX]

It seems to do it mostly after the computer has been off for several hours.

Apply new thermal-paste between CPU and cooler, other than, what CoffeeFiend said; that looks like a capacitor plague so check he ones inside the PSU and on the mobo .

[VideoRipper]

Just to show you the difference between good and bad (blown) capacitors:

Greetz,

Peter.

[mike13]

Problem solved (Pretty sure). I replaced the power supply with one from another computer I was saving for parts. It did not exactly fit the case,

but I was able to make the connections to at least try it. I started the computer, and it is still on, after about three hours, with no reboots.

So I am pretty sure the power supply was bad. One question...the old / defective power supply has an extra harness with four wires, two black and two yellow that also connected to the motherboard. The power suppply I have in it now, does not have that harness. I have no idea what that harness is for, but everyting seems to work so far. The old power supply is a Allied, Model AL-C350ATX. When I get another NEW power supply, do I need one that also has that harness, or is it not really needed ?? The motherboard is a (P4M800-M7 A). Many thanks to everyone who offered advice and suggestions, it is appreciated. !! Mike

[cluberti]

Note that particular power supply model has been known for bad caps since at least late 2006 (just make a google search and you'll see what I mean). As to the harness, I honestly couldn't tell you what it is, as I've never seen a motherboard require a plug like that for power, and I haven't seen any retail power supplies that have that connectoid either - however, I built only a small few P4 machines in my day, as I was more a fan of AMD at the time, so it may be something that cheaper Biostar/ECS motherboards required from the PSU for the P4 processor on the board to get adequate power (which wouldn't be required anymore with newer PSUs from today). Otherwise, honestly, not a clue as to what that little black plug is for - it's very flat, so it's not an additional 12v rail, and it's not a fan power plug either.

[puntoMX]

... Otherwise, honestly, not a clue as to what that little black plug is for - it's very flat, so it's not an additional 12v rail, and it's not a fan power plug either.

Single SATA power plug, cheap a** PSUs have only one SATA plug, and some, like that one, have not the 3.3 line connected for SATA either .

One question...the old / defective power supply has an extra harness with four wires, two black and two yellow that also connected to the motherboard. The power suppply I have in it now, does not have that harness. I have no idea what that harness is for, but everyting seems to work so far. The old power supply is a Allied, Model AL-C350ATX. When I get another NEW power supply, do I need one that also has that harness, or is it not really needed ??

Yes, a new PSU will have the 12V P4 connector you are talking about (2 yellow 12v, 2 ground/neutral in black), I'm surprised that the motherboard even started. Get a brand PSU, Coolermaster makes cheap ones for example and they last. Don't buy Ultra, Rosewill or that kind of stuff...

By the way, 20 or 24 pins ATX, all the same, just go for a 24 pin (yes, it will fit).