Why do my PC fans spin really fast and no startup?

"Hi @random_user_101 ,

What is the make and model number of the desktop computer or if it is a custom build the make and model number of the motherboard?

It may be that the BIOS is corrupted and it can't POST properly.

Disconnect the AC power from the computer and check if there is a button cell battery on the motherboard.

If there is gently remove it (note the orientation so that you replace it the correct way) and then press and hold the computer’s power button for 10 seconds and then release it.

Reinsert the coin cell battery , reconnect and switch on the power and then try to start the computer.

If it starts OK if may be that the battery has been depleted and needs to be replaced.

Be aware that this will restore the BIOS settings to their default value, so if you had any settings tailored for specific hardware/operating requirements you’ll have to go back into BIOS and change them back to what you had

This battery maintains the BIOS settings when the PC is powered off and when it starts to deteriorate the settings could become corrupted.

They usually have a life span of 5-7 years and are not the rechargeable type."

"To make sure that there is not a short circuit unplug everything from the motherboard, including add-in cards, but not new power supply - make sure the ATX_12V is connected as well the main ATX power connector.

video cardmodemsnetwork cardsAll drives - hard drive, CD/DVD drives and floppy.etc. take them all out.How many RAM chips? If two try taking one out at a time. Sometimes unseating and reseating will fix a bad contact.

Also shake the case to see if there is a loose screw some where causing a short circuit.

So now you should have the monitor plugged in, the keyboard and the power supply that is it!

We are trying to eliminate possible causes of our problem.

O.K. now try turning it on. Does anything appear on the screen? Are the fans spinning?

If yes to both go into BIOS and set to defaults.

Then try adding the hard drive with Windows on it. Did it boot up?

Let me know how it goes.

In 35 years I come across maybe about 5 motherboards that had a natural death. Quite rare, well apart from some one spilling liquid on it or the like."