Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

i have strange problem with my computer. i tried to turn it on, the computer was started ok, but i didnt see anything on screen.

i tried to understand what cause the problem. its was'nt the HD or the screen. when i opened the computer, i saw that the fan connected to my motherboard didnt work.

the funny thing is that i drove to a friend of mine, so he would fix me the computer, and when we tried to open the computer there it worked somehow and the fan worked also.

when i came back home the computer again didnt work and the fan didnt work as well.

does someone know what can cause the problem?

share|improve this question

Try connecting the fan to another connector to make sure, but sounds like you got a dying fan. Does it make any odd noises when it does work? If this is the processor fan, I would make sure to replace it and make sure it is working properly.

Make sure all the power connectors are secure too and make sure everything is clean.

If the computer stops working and the fan at the same time, there is also a chance you are having random power supply issues. I would start making sure the fan works first though. Start with easy cheap parts and then move up.

With some systems, there is the main 20/24 pin power connector and a additional 4 or 8 pin motherboard power connector. Make sure everything is plugged in securely. I get the feeling though you are having power supply issues if it randomly works fine and then nothing.

share|improve this answer

The root cause is not the fan. Lack of a fan on the heatsink of a motherboard chipset (or even on a CPU) will not cause enough extra heat quickly enough to cause the system to fail to boot properly.

Barring the obvious stuff (is everything plugged in? Is the connection between the monitor and the video card good?) my guess would be an issue with the power. It could be that your power supply is overloaded and/or not very good. If the power is cleaner at your friend's place than at yours you could see this sort of problem.

share|improve this answer
I'm not so sure. I've had a couple CPU's (coughAMDcough) over the years that heated up so fast that you'd barely see the POST start before it would freeze when used without a heatsink/fan. – Brian Knoblauch Dec 2 '09 at 21:11
Right. Lack of a heatsink will cause rapid problems, especially on older CPUs without good thermal throttling. Lack of a fan on that heatsink will not cause problems very quickly from a cold start. It probably won't cause problems at all unless the system is under load. – Captain Segfault Dec 3 '09 at 0:00

When you took the computer to your friend's house and plugged it in it worked correctly and when you brought it back home and plugged it in it did the same thing as before?

While at home try plugging it somewhere other than where you had been plugging it in. Somewhere on a different circuit/breaker preferably. You may be having issues with the source of your power.

share|improve this answer

Barring location power issues (see ongle's answer), the trip probably jarred the fan connector.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.