Cpu fan i had a desktop computer...last two days ago there's a problem posted with black screen before the booting of my pc or windows...it says,CPU fan not detected....there's a choice there that if i press F1,windows will boot... thats why i can use it now,my problem is,why my computer posting that my CPU fun was not detected even though its ruuning of functioning after i boot my computer..? tell me how to troubleshoot my pc..thanks a lot...

It isn't detecting your fan as the fan may be dead or the sensor is dead. Both are not repairable but cheaply replaced and fixed with a new fan. The cost of the replacement cpu fan is not that much compared to a cpu. So don't try to make it last a bit longer by hitting the f1 to continue. That will catch up with you pretty quick.

If you want to double check you need to look at either the cmos setup section of a system monitoring software and check to see cpu fan speed and cpu temps. You may not see the speed but you should see the temps. If the temp is getting over 55-60 or more shut down and go get the fan. It's dead. If you see the rpms showing then you might have a motherboard problem.

However I would say you have a dead fan. Replacements are $5-15 and you need to just crack the case and pull the old one and put in the new one. You can take it to a tech but they will charge you to check it out again and then ti replace the fan and some shops will insist on new heat sink etc (those don't ever ever wear out or go bad at all)

Hi
Recheck the wires connector of the cpu to the motherbord.
If connectors are plugged ok and still having problem consider replacing the fan with new one .
somtimes even when the fan is turnning it is not fast enough to get the cpu cooled.
there are some free wares that can hlp you monitor thr cpu and the cpu fan performance, I'm using speedfan.

hope it helps

The fan needs to be repalced