Thinkcentre freezes and sometimes goes to blue screen

[dm_murphy]

I own a thinkcentre m55 8810-fbu with Pentium D-3.0 Ghz, SATA HD, with Windows XP Pro SP3 installed.  This is a small form factor desktop.  My problem is that the machine destabilizes after about an hour.  I notice lots of wavy line activity on the monitor, the fan revs up some and then it disconnects itself from the internet.  After that I have about 20 secs before it freezes.  I have to power down with the power button to get out of it.  It will boot up again and is operable again for a limited time. When I open the cover, I notice the CPU to be very hot (almost too hot to touch) and the hard drive hotter than I would like to see it.  This unit only has one vent fan.

I have reloaded windows which got rid of the blue screen and memory dumps but I have no confidence it won't keep happening.  I have flashed the BIOS with the latest revision available (2jjy49usa - 12-12-2008).  I have reconnected the SATA drive and memory modules.  I don't know that it helped any.  What should I be looking at to rectify this problem?

[Mornsgrans]

Please veryfy, that the CPU-fan is running after turning the ThinkCentre on. If not, the fan must be replaced.

You also should take a look whether the ribs of the fansink are free of dust. The ThinkCentre works like a vaccum-cleaner and the dust locks the ribs ather a few months of use.

You can clean the fansink with compressed air after plug off the fan-power-cable from the board. After that job re-attach the fan-power-cable and test the temperature again.

[dm_murphy]

Thanks,

The fan works and the heat sink ribs are clean.  I am going through a hard drive rebuild because the company I bought the computer from shipped me a new drive because at one point I was getting delayed write errors.  I will see how this goes.

[dm_murphy]

I am going to replace the fan as a matter of course to eliminate the possibility that the one in the machine now is on its last legs.  It it does not help, I will have a spare.