CPU fan not working - but PC runs ok for over an hour

[jj14]

Hi! A friend of mine walked in with his e-machines PC stating that it runs ok for between an hour or two, but then shuts down completely and doesn't start for quite some time.
This has a P4 2.8 GHz CPU with 512MB RAM (Win XP). The cpu cooler looks like the stock Intel cooler, but the CPU fan didn't look like anything that I've seen with stock Intel coolers. It was a fan mounted on the top surface - screwed into the fins of the cooler - anyway, this thing was covered with dust and the fins were horribly clogged with dust. Turned it on and the fan doesn't turn. But the PC turns on (though ridiculously slow) and worked fine for about an hour or so - in this time, I ran speedfan and the remote 1 temperature reported was 98C, but all other temps were between 35-45C. Not sure if speedfan is reporting the right temperature.

I thought that the CPU should have throttled long before the 1 hour or so - how did a P4 get to run for an hour or so without any active cooling? (With the amount of dust caked onto the fins, I'm not sure how effective the 'passive cooling' would have bee either.

I have a spare Intel cooler for an old P4 (Prescott core) - is it ok to swap the cooler with this? In other words, are the stock intel coolers the same for all P4s? (I don't know what core the P4 is in the e-machines. (Of course, I will clean and reapply the AS5)

 

[dmroeder]

The CPU probably is throttling right away, that's why it's ridiculously slow.

The heat sink is providing some cooling, just not enough. You really need the fan. I would just re-apply the thermal compound and replace the fan. It was probably an 80mm one, but you can measure it to find out.

It was probably one looking like this.

 

[jj14]

Thanks dmroeder. You are right - it looked similar to that fan, (a lower profile - thinner one though) - I forgot to measure it yesterday, but it looked closer to 60mm (I could be mistaken though).

In case I don't find the same fan, would it be ok to replace the heat sink and fan with the spare that I have (image below) Or are these non-interchangeable?

 

[Zorg]

You will be able to find a fan that you can screw on there. It might not look right but if it fits, has the same number of wires and is at least as fast it will work. Try to get the fastest one you can, but don't go too much over the wattage listed on the original fan. If you want to change the HS, then you need to check the mounting to verify that it is the same.

 

[dmroeder]

I wish I could help there jj14, but I don't know about P4's or e-machines. If I were to guess I would say that any P4 cooler would work, but you know where assuming gets you!

 

[jj14]

thanks guys. I ended up calling Intel and they said that for processors over 2.8GHz, there is a different HS/fan, but for 2.8 and under, they are the same

 

[michiganteddybear]

while that is correct, the mounting of some of the emachines (and other large OEM's) is not the standard intel spec'd mounting. you will need to verify the OEM fan from intel (what you had pictured) will work.