Replacement PSU won’t boot (CMOS clearing)

If the PC does not boot up after the power supply has just been replaced, Seasonic recommends clearing the CMOS memory of the motherboard to reset the motherboard to its factory default state in order to clear the settings related to the previous power supply.

Listed below are a few common methods to clear the CMOS in this situation; however, Seasonic suggests you consult motherboard’s user manual to reset the CMOS.

Reseat the CMOS battery

1. Unplug the power supply from the AC mains.
2. Locate the CMOS battery, usually a button cell, aka, watch battery, on your motherboard.
3. Remove, then reconnect the battery.
 

Use a clear CMOS jumper

1. Unplug the power supply from the AC mains.
2. Locate the jumper on the motherboard; it is often labelled CLEAR CMOS.
3. Follow the instructions on the motherboard’s user manual to short the pins using the plastic jumper.
4. Plug in the AC power, then turn the computer ON to make sure the BIOS has been reset.
5. Turn OFF the computer, and set the jumper back to its original position.