Windows XP Sudden Shutdown but CPU is cool


A DFI LanParty UT with an Athlon X2 3800 has been gradually failing. Throwing memory errors and now has sudden shutdown problems. It is very nasty figuring out what is wrong. If you read posts on sudden shutdown, folks often blame (so things you should try if you’ve got similar problems):

# Heat. This is the case when the machine really does just shutdown. The Athlon has a kind of rude thermal protection. When it gets too hot on an Intel machine, the CPU just throttles down, but on the Athlon, it would just melt and catch fire. The quick fix was that when the Athlon X2 came out was that if something got too hot, the BIOS would suddenly shut the machine down. In looking at the BIOS, the temperatures looked fine, but the fan speed appears to show fluctuations to zero. “Tech Republic”: reports that if the BIOS sees the fan speed of the power supply or CPU drop to zero, it will automatically shutdown the machine. In looking at the fans they are spinning, so I’m guessing the fan speed is not being correctly reported. So go to your bios and check.
# The most common problem though is an overheating CPU. One thing that is not obvious if you have a do-it-yourself machine is that you don’t lather a lot of thermal paste on the CPU. This actually reduces cooling which is not intuitive, so you want just a thin, thin layer. I did this wrong and when I wiped all the paste off on another machine, temperatures dropped from 65C to 45C, so this makes a big difference. Not the problem in this case
# The power supply is dying. This can also cause a problem so you want a high quality power supply. I’ve also had problems where there is not enough voltage in the supply to run everything. This is a big problem with power hungry graphics card. In this case, there are four hard drives in it and a big graphics card and the X2 eats power, so it could be the power supply is failing. This does happen and the only way to know is to first try to take drives out to reduce the load or if you are impatient, just replace the supply.
# There is a “RAM”: memory problem. Bad memory might be it. The machine occassionally on start reports bad memory problems. The quick fix is to replace the memory. I’ve been running this thing overclocked and most of my overclocked machines have memory failing every two years or so. It has a pair of 1GB memory in it, so the quick fix is just to replace the memory. In this case, though I first ran memtest and it ran fine for 8 hours but did crash even running non overclocked. That’s suspicious so maybe just replace to be sure.
# A short in the motherboard. This is a bad one as its impossible to find and in that case, I guess the only answer is to buy a new computer or a new motherboard if you are ambitious. The problem of course is that on this machine it is three years old, so everything from the Athlon X2 to the socket to the memory is now obsolete, so just getting a new iMac or Macbook is way cheaper and plus you get three years service. Being philosophical for a DYI machine, three years is a long time. Just make sure you’ve backed everything up!

Net, net, my money in this case is on fan not being reported correctly to the BIOS, next up is replacing the RAM and seeing if I can run memtest for 24 hours are least. Finally, unplug all but the boot drive and see what happens. It does appear somewhat thermally related as later in the day it won’t even get to the BIOS before shutting down. I wish the BIOS would report that it is doing the shutdown, but the Athlon BIOS were just hacked for this thermal problem. Literally, the CPU shuts down without anywarning.

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