The P5WD2-E motherboard from ASUS was released in 2005. If there are problems with the motherboard powering up, there are three different causes. Additional troubleshooting resources can be found on the ASUS website.
Connections/Source
Make sure that the power cable is firmly connected into the power supply unit (PSU) and the power supply. Check that the power supply is functioning properly by testing another device. Try an alternative power cable if possible to see if this is the root cause.
Power Supply Unit
If the power and power cable are working, but the PSU does not switch on (check for fan activity), the unit is faulty. Check that the on-board power switch is set to On (if there is one) and if possible replace the PSU with another model.
Motherboard Problem
If the PSU springs into life, but the motherboard does not switch on (check the on-board LED light), there is a problem with the motherboard or the connections between it and the PSU. Consult the documentation supplied with the board and the PSU to see where the connecting cables should go and ensure they are firmly seated. If there is still no power, this suggests a faulty motherboard.
Tags: power cable, power supply, Check that, does switch, does switch check, switch check