Trouble turning system on

[Squid_uk]

If i have used my system and i shut it down, when i come back to turning it on it it really weird it won't respond to the on button on the front or the on/off on the rear the only way it will stay on is if i disconnect the power lead and plug it in again which is when it starts up without any button being pressed, any ideas what could be causing this?

[ROF]

Faulty power supply. I'd buy a new one soon before it causes other parts to fail.

[redwudz]

The simple explanation could be your power switch is defective. Try unplugging it from the motherboard and substituting the leads from the reset switch. They work the same way.

Next would be either a problem with the motherboard 'sense' circuit for the power switch or a problem with the power supply.

The front power switch just sends a signal to the MB to tell it to turn on the power supply. Most newer PS's keep part of the MB alive and sometimes the RAM memory. This is why unplugging it works. The power bleeds off those circuits after a couple of minutes, effectively resetting everything.