Just noticed my PC feels very hot.

Ran a program to check what's going on:


Yikes!

Is the fan working properly and is there sufficient air flow around your PC?

I just opened it up - there is a fan on the CPU - on and working fine. Fan on the hard drives - on and fine. Fan for the PSU -on and fine.

But the one key link - the case fan, at the back of the case, is off for some reason.

The lack of any venting (out the back is making the other two fans almost useless.

The wonders of physics......

CPU is also at 83% load.

I'd suggest stopping some of your CPU-intensive programs until you can fix that fan problem.

I've taken the side panel off, which has caused the temperatures to fall to 75 degrees.

I'm guessing it has been running like this a couple of weeks. I noticed it was slow, but didn't twig why. I hope I didn't break anything.

Fans fail. It's a fact of computer life. They generally simply snap out. You'll generally find they are powered from taps on the octopus of the power supply wiring--follow the wire back from the fan and you'll generally find it goes to a small segment of wire with plugs on both ends, generally connecting two wires.

If you're lucky and it's at the end simply unplug it and take it down to a computer place to get a replacement. If it's in the middle unplug both ends and plug them back into each other after removing the little segment that the fan was connected to. The plugs are often quite stubborn and many of them don't enforce the pin alignment too well--you'll have to hold the wires straight to get them to plug in.

Once you have the replacement it doesn't really matter where it connects, just find an open end of the octopus and put it there. In the remote chance there isn't one you'll have to unplug something and plug the fans' connector in and the thing you unplugged into the other end of the fan connector.

I have seen a few fans powered off the motherboard--these let the system monitor if the fan is spinning. I haven't encountered one of these in some years, though.

It's possible there are other proprietary systems I haven't run into--my main job is software, not hardware.

They're generally one of a few standard sizes - 120mm, 92mm or 80mm. If it's a standard, you can get a replacement at someplace like Best Buy. If it's a different size, you might have to go to a bigger place like Fry's or order it online.

http://www.newegg.com/Product/ShowIm...B%20Case%20Fan

That's a pic of the connector types you might see on the fan. The stubborn plugs that Loren talked about are the bigger 4 pin plugs. The ones directly on the system board are the smaller 3 pin ones.

I think the motherboard powered ones are more common these days, so that the system can monitor the fan operation. I looked at a bunch of fans, and the majority of them come with both types of connectors.

Even if all the fans are running sometimes the thermal seal between the CPU and the fan on top of it will fail. This connection has the most impact on CPU temperature.

I agree they will be in both forms. However, it's been a long time since I've seen anything but a CPU fan powered from the motherboard.

His problem is a case fan, not the CPU fan.

Without the case fan, all you have is a convection oven in there with the CPU and other stuff as the heat source.

I disagree. It depends on the style and size of the case. In many machines the PSU fan along with passive venting is sufficient, thus the suggestion to check the soundness of the CPU to CPU fan connection. It has by far the greatest impact on the CPU temperature. But let me clarify this by saying to only check this if the high CPU level persists after changing the dead case fan.