CPU fan issue

[robinglow]

If you hear the CPU fan is running and the monitor power is still on, but you did not see any thing show up in the monitor screen. What would you do to find out what is going wrong? (Asked by WNI people)

[Hack]

Moved To General PC

[MarMan]

Add 3 ounces of oil to the fan.

Just kidding; don't do that.

Trying to figure out what is going wrong can be extremely difficult and time consuming. Often professionals don't even try to figure out what is wrong. They just figure out how to make it work. Technicians rarely even diagnose circuit boards anymore. It is cheaper to buy a new one..

To try to fix your problem you can determine what causes it. If the problem is intermittent; good luck. The chances of finding out what is wrong is slim, and anyone who could would probably charge you over 10x what the computer is worth.

Can you reproduce this problem? Does it happen after a certain amount of time or when you use a cpu intensive app? Then a component is probably over-heating. You can narrow it down by spraying that cold stuff (can't remember the name of it) on different areas. Does it happen when you use a certain device? You can also remove all non-vital devices and see if the problem goes away. If it does then you can add them one at a time.

Could be a basic windows instability, could be a bad PC.

[techgnome]

first thing I do is swap monitors... sure, power maybe flowing, but it's still possible the monitor is bad. IF possible, swap cables. When that doesn't work, I pop open the case, make sure the graphics card is seated properly, swap it out if necessary... check the CPU fan (not the PS Fan), and the heatsink, make sure that is all still good...

if all that fails, I get a new PC, keeping the old one for parts.

-tg

[FireXtol]

Usually I suggest removing all extraneous components. CD-ROM drives, hard drives, USB devices, external hard drives, etc.

You should be left with no more than PSU, motherboard, CPU, RAM, and video. (even try without a keyboard if needed, mouse can definitely be disconnected)

Do you have a PC speaker? You might want one. Often the motherboard can alert you to the problem.

If not replace one of the key components one at a time with a known working part, if possible, and continue until you find the defective part. I'd suggest you start with the video card(if discrete) and the RAM(if you have multiple sticks). The others could be a little trickier depending on what you have available.

[stanav]

There's no magic in trouble shooting a PC. It's just an elimination process as others have mentioned. You first make sure that the monitor is working. Most monitors now these days have built-in self-diagnostics. You just power the monitor off, disconnect the video cable to the computer and power it back on. If it's working OK, it will display some kind of "no signal" message on the screen. Next is the computer. Unplug it from power, press the power button as if you're trying to turn it on. This will help discharge all the power stored in capacities. Now plug it back in and turn on. Listen for error beeps. No beeps and no go? pull the power. Crack the case open and pull the RAM. Power it back. You should hear some error beeps now (because there's no RAM). If not, it's likely the motherboard or the CPU and it's not worth it to go further. If you hear the beeps with no RAM, turn it off. Put the ram back. Remove all components but the video card, ram and keyboard (also reseat the video card while you're at it). Turn it back on. Still no go? Try a different video card. Still no go? Buy a new computer

[Lord Orwell]

i would just add that swapping components for known good ones may not always be a good idea. I had purchased a motherboard from a local computer store labeled as an "open box item". It turns out it was an rme board and upon powering it up it fried the ram chips and video card. I mistakenly assumed i had inserted a bad video card to start with and swapped in my 9700 pro, which i paid $400 for, and it also got fried. All Computers Plus was willing to do was give me half-off on a new motherboard. This is one of the reasons i shop on line now.