Fans still work work even after shutdown

[mahiarirani]

Hi, I assembled a new PC months ago and it was working fine without any problem till now. I've just shutdown my computer like everyday and it's when this solution came up. After my PC turned off, I noticed that my case fans are still running but not normally. Actually they are working more slowly and the brightness of the LED's of the fans are like 50%. I've turned on and off my computer for several times but it didn't help. I even hard shutdown (hold the power button for several seconds) my PC but didn't work either. And it's not just about my PC fans, my USB plugs are also working. I've disconnected the power to my PC but nothing changed !!! I've turned the PSU off, Unplug my wire but they were still working. So I think they are using my MB battery cause there is no other power supply to use ! I don't know if this situation is going to damage my computer or what. Here is my PC configuration detail:

MB - Asus B85-PLUS
PSU - Green 380watt
CPU - Int Core i3 4160
GPU - Galaxy nVidia 450gts
RAM - 2 x 4GB HyperX

Looking forward to your helps

 

[brispuss]

It is doubtful that the motherboard 3V button battery is able to supply sufficient power to run fans even at reduced speed.

It is assumed that the PSU has been disconnected from the mains (house) power supply but its secondary (computer/motherboard) side cables are still connected to the motherboard and other components.

What is more likely to be happening is that the PSU is still supplying some power from its capacitors (capacitors discharging) to the system even though the mains power to the PSU is now disconnected/switched off. This suggests there may be a problem with the PSU as it should not supply power to the system when the PSU has been completely switched off/disconnected from the mains.

To check this, with the mains power going to the PSU switched off or disconnected, disconnect the cables from the PSU to the motherboard and other components, and see if the fans still run or not.

If the fans stop running then the PSU may be faulty. Try another known working PSU, and/or try this Green PSU in another computer to see if the fans etc run when the PSU is shut down/switched off.

If by some remote chance the fans etc continue to run after the secondary cables from the Green PSU have been disconnected from the motherboard and other components, then other solutions will have to be found.