PC shutting down for no apparent reason

Yorky

The automatic stand-by function seems to be working correctly on my PC but it shuts down automatically for no apparent reason periodically and won't start up again. The power supply has to be turned off several times to get it to start up again from fully shut-down not stand-by mode.

Any ideas why this would be happening?

mensreas

It sounds viral except the part about the psu try reseating all the hdd power cables hope this helps

mr

Auvers

need a bit more info.
Does you PC shut down when under load?
what are your specs?
What is the temperature of you CPU?

Bogger77

Sounds like over heating
is the CPU fan running?

eamon234

very possibly overheating are your fans working ok? Installed any new components lately that may be raising the temperature inside you casing?

Anti

Bogger77 wrote:

Sounds like over heating
is the CPU fan running?

Bang on the money. This is typical behaviour of a overheating pc.

Yorky

I've just vacuumed all openings on the rear of the CPU to ensure that dust is not causing it to overheat. Under the Events Viewer at around the time this last occurred it states 'TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts'. Would this mean that it has a virus?

ActorSeeksJob

Let's check if it has a virus, do this for me

Please download the self-extracting version of HijackThis from here:

HijackThis_sfx download

Save HijackThis_sfx to your desktop.

Double-click the file then click the Unzip button. Then close the Self-Extractor window.

Using My Computer/Windows Explorer, navigate to C:\Program Files\HijackThis and double click on HijackThis.exe to run it. If you would like to make a shortcut for your Desktop so it's more easily accessable, right click HijackThis.exe and choose Send To > Desktop (create shortcut).

Please run the extracted HijackThis.exe from now on. Delete any copies of HijackThis.zip that you have saved.

Open HijackThis and click Do a system scan and save a log file. Copy the entire contents of that log and post it here

Ponster

Yorky wrote:

I've just vacuumed all openings on the rear of the CPU to ensure that dust is not causing it to overheat. Under the Events Viewer at around the time this last occurred it states 'TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts'. Would this mean that it has a virus?

Nope. It may be just a normal XP Service Pack 2 message.

If you use P2P software and haven't modified your setup to allow more concurrent connections this can happen.

Anti

Ponster wrote:

Nope. It may be just a normal XP Service Pack 2 message.

If you use P2P software and haven't modified your setup to allow more concurrent connections this can happen.

Windows XP SP2 limits the maximum concurrent half-open connections (SYN) to a maximum of 10 (the previous limit was over 65,000). This is supposed to slow down certain viruses because their spreading strategy is to connect, to a high amount of random IP numbers. The drawback to this connection limit is that other network intensive applications can be slowed, including Peer-to-Peer (P2P) clients.

An unofficial patch will modify the locked TCPIP.SYS and let you set the limit to whatever you wish. 50 half-open connections is a reasonable limit or you can set the limit back to 65,535 which it was before Windows XP SP2. The patch is called EventID 4226 Patcher and can be found on LVL Lord's web site: LVLlord downloads - http://lvllord.de/?lang=en&url=downloads

witnessmenow

Yorky wrote:

I've just vacuumed all openings on the rear of the CPU to ensure that dust is not causing it to overheat. Under the Events Viewer at around the time this last occurred it states 'TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts'. Would this mean that it has a virus?

Dont vacums generate a load of static? Isnt static really bad for the insides of pcs? Carefull vacuming pcs! Id say the above are right about the overheating cpu. Does it only happen when you running labour intensive applications(E.g Games , Converting video etc..)?

Yorky

PC has started doing this again, only when not in use. It's as if it has gone into stand-by mode but when the CPU button is depressed nothing happens. After several attempts it will work-any more ideas?

Ponster

You never told us if the problem went away and if so what you did to fix it.

Yorky

I vacuumed out the CPU and it didn't shut down again until yesterday. Seeing that was the first time I had ever done this in two years it couldn't need doing again already.

Yorky

Could be faulty Power Supply Unit. Took out the PSU and it is an Enlight GPS-250AB-100K and the only reference to wattage is 'Peak:300W Rated:250W'.
Which wattage should I be looking for in the replacement PSU and are all plugs the same? I've got an AMD Sempron 3000+ Processor, DVD player,DVD recorder and floppy.

Thanks for the replies.

WetDaddy

I agree that it's likely to be a PSU issue (given that it's not overheating). Just a thought, it could also be a grounding / shorting issue... Have you moved the box recently? Is it in a different room or with different environmental factors?

Cuddlesworth

What are you running on the pc when you leave it?

stevejazzx

run
http://www.almico.com/speedfan432.exe
and post tempratures of the cpu
what hardware do you have in there.
remove for the moment any big independantly powered graphics cards (run system from onboard video if you have it) this will free up the power supply

papu

open up the sides of the case , take it out from under a desk ( if it is under a desk) and if you ahve a desktop fan blow it at the open side and see how long it lasts?