Poweron does not turn on PC?

I recently had a similar problem. Try this. Inplug your computer from the wall. Open the case. Unplug all connectors from the mother board until all the motherboard lights go out. Leave the machine that way for 15 minutes or so. Reconnect the mother board plugs. Connect to the wall power. Give it a try. If this works, great but in any case it is probably an indication of a failing motherboard and/or power supply. Check the motherboard manufacturer for bios upgrades too.