PC shuts itself down and reboots ??

[fluffy]

I'm sure I've seen this before on this forum, but can't find it again.
I've got a new motherboard and chip, and after a while the PC just shuts down and reboots.
Bought a new fan, seemed to help a bit.
Then started to take ages to boot up, and often just hung.
Started in safe mode, and then could boot up.
I have AVG 7 as antivirus and have scanned drive.
Am currently reinstalling windows AGAIN, and downloading the service packs etc.
Anyone got any other ideas about the reboot problem?
Any help much appreciated.

[Plotloss]

In order of what I reckon the issue is:

Heat
Lack of PSU Power, new board may draw more current
Bad Memory Stick
A.N.Other hardware fault

[fluffy]

Seems to be triggered either when there is a lot of hard drive access or if its left on for several hours.
If it shuts itself down abruptly, could this be causing it to boot up slowly due to corrupted files as it wasn't shutdown properly?

[Plotloss]

Yes, when Windows ab ends it tries to rectify what it can on next boot which is basically rehashing the registry from a stored copy.

[Liszt]

Plotloss said:

In order of what I reckon the issue is: Heat Lack of PSU Power, new board may draw more current Bad Memory Stick A.N.Other hardware fault

To that list have tried applying the Blaster patch?

If it is a heat problem try running with the case cover off.

Is there a temperature readout in the BIOS?

[Podie]

Plotty... outside bet could be the good old RPC error....?

[puggit]

I had this over the weekend - turned out my registry corrupted.

Although in your case does seem more like overheating hardware

[d3ano]

I would put it to over heating.
I have a 2.8P4 that was doing this. I put a water cooling system in and i've never had a problem since.
It helps to have a good PSU too min of 400watts.

[fluffy]

Many thanks for all your help. Will try leaving cover off, and see if that helps. Otherwise, I know a good window where it might end up visiting.

[andyf007]

Cooling has always been a big issue with machines since the introduction of the P2, and if your upgrading only the board and the chip, chances are the case will not be up to the job. A new processor fan will only move the air around the inside of the case, much like a fan oven. You need as much extraction on the case as you can get. Fit an additional fan(s) to the back of the case (there should be grilles there you can use). Make sure they are blowing in the right direction. Alternatively invest in a better case, with plenty of extraction and an uprated PSU.

As has been mentioned, check the bios for any temperature monitoring of the chip, leave it on this screen for a little while. If this reads above or close to the alarm levels, then you need cooling, because at this point the processors aren't even working yet.

Bear in mind the environment as well. Hot or warm rooms are not helpful, as is tucking them into small spaces behind desks etc. They need room around them, especially front and rear. While we're on the point, check that there is sufficient air inlet on the front. I know of many cases that only have a small gap at the bottom of the front cover, which is almost useless at ducting air, especially if it's stood on a carpetted floor.

My best suggestion is to buy a better case though.

Andy

[dern]

Mine was doing this with ever increasing frequency last week. Started rebooting once a day and ended up rebooting itself within 5 minutes of booting up. I replaced the power supply and the problem went away. The new PSU was slightly upgraded but whether that was the solution or the fact that the old supply had simply worn out I don't know.

You can download applications to monitor temperature overtime (I haven't got the urls to hand) and then you can see if the reboot time correlates with a rise in temperature. If it isn't you need to do memory tests and so on to narrow it down. My temperature stayed pretty constant and didn't seem to peak at reboot, the memory checked out ok and a new power supply was cheaper and easier to install than a new motherboard. If the power supply hadn't fixed the problem the next step was a new motherboard.

Mark

[fluffy]

All seems OK so far.
New cooling fan in case seems to be doing the trick.
Left case slightly open at side to allow extra air flow.
Many thanks for all contributions.
PSU only 300 watt, so with a 2.8GHz Celeron processor might be next thing to upgrade.

[130tdi]

To check the memory try a copy of this iso from memtest86.com

We had a similar problem at work, turned out to be 2 dodgy strips of RAM.