Biostar a870u3 motherboard power problem

[Simon Hawk]

Hello,
All (3) case cooling fans stay running, even if the case power switch is turned off. The only way to completely turn them off is to use the PSU main power switch. Advice is appreciated

 

[clutchc]

If the fans are wired to the motherboard, the motherboard is at fault. If the fans are wired directly to the PSU's cables, it could still be the motherboard. It should send a signal to the PSU to shut down. Or the PSU could be receiving the signal, but not obeying. Try unplugging the 24 pin cable to the board and reseating it. If that fails to solve your problem, you either have a faulty board or PSU.