19-08-2024, 12:32 PM
Occasionally removing the actual AC mains cable (if there is no real on/off on the back of the PSU) for a few minutes resets the 5V standby supply.
There is likely a header marked PWR on MoBo with two wires to the front panel. It may be grouped with HDD LED, Power LED and speaker. Those panel switches can stick or be intermittent. It needs a momentary connection to turn on or initiate shut down.. So try a momentary switch on the MoBo pins.
As Mark says, sometimes the PSU is faulty, but I've never investigated if it was the standby or a main fault. Sometimes there is a standby PSU LED on the MoBo.
Likely if you lost the MoBo manual it is on the Internet. The manual shows which two pins are on/off by momentary action. Some don't turn on if the button is held down. Others "reset" something in PSU (maybe after a short on a disk drive cable) if the button is held long enough.
There is likely a header marked PWR on MoBo with two wires to the front panel. It may be grouped with HDD LED, Power LED and speaker. Those panel switches can stick or be intermittent. It needs a momentary connection to turn on or initiate shut down.. So try a momentary switch on the MoBo pins.
As Mark says, sometimes the PSU is faulty, but I've never investigated if it was the standby or a main fault. Sometimes there is a standby PSU LED on the MoBo.
Likely if you lost the MoBo manual it is on the Internet. The manual shows which two pins are on/off by momentary action. Some don't turn on if the button is held down. Others "reset" something in PSU (maybe after a short on a disk drive cable) if the button is held long enough.
