I have a 4 years old Asus B75M-A motherboard that failed to power on. Pressing the front panel power switch or shorting the on-board power on pins, the cpu fan turns briefly then stops. Below are what I've tested so far:
- Test the psu alone with green short to ground, all voltages ok
- Measure the 5VSB on board, ok
- Use the psu on a known-to-work motherboard (another Asus) showed that the psu works
- Use this problematic motherboard with a known-to-work psu, same problem
- Check the capacitors (all are aluminum cased) on the board, all looks fine
There were other intermittent problems before it reaches this total failure:
- usb HDD couldn't be started, even usb thumb drive couldn't be detected
- reboot itself without a reason
I wonder if cpu or the board is the cause and how it can be repaired. Please help.
- Test the psu alone with green short to ground, all voltages ok
- Measure the 5VSB on board, ok
- Use the psu on a known-to-work motherboard (another Asus) showed that the psu works
- Use this problematic motherboard with a known-to-work psu, same problem
- Check the capacitors (all are aluminum cased) on the board, all looks fine
There were other intermittent problems before it reaches this total failure:
- usb HDD couldn't be started, even usb thumb drive couldn't be detected
- reboot itself without a reason
I wonder if cpu or the board is the cause and how it can be repaired. Please help.
