Computer won't power on

[ck87]

My computer worked normally up until today. I pressed the power button to turn it on and nothing happened. When I open up the pc and press the power button, the cpu and case fans spin for about one second. I tired disconnecting everything unnecessary and it still wouldn't power on. Afterwards, I connected my power supply to an old mobo. This mobo has a green light that would turn on, but when i activated the power nothing happened. Is this the power supply causing a problem? It's a 300w antec thats several years old. Prior to this the only hardware change I made was to add a new usb keyboard. I've also always been getting "driver_irql_less_or_not_equal" bsods, but i assumed it's a software problem and have been unable to solve it. How can I get my computer to boot again?

Athlon 64 3000+
Radeon 9500pro
Chaintech VNF3-250
Antec 300w PSU

 

[Harvey]

300 watts is probably not enough for an Athlon 64 system. You didn't say what the second board was.

Even so, since it worked until now, it sounds like the PS is bad. The green LED on the mobo show that the power supply is connected, but it uses a separate standby supply that is always on for such functions as "Wake on alarm" that, in turn, power up the main system.

Try another supply. If you need a new one, and you live near a Fry's Electronics, these may help:

Ultra X-Finity 600 W supply for $39.99 after rebate.

A better choice may be this Antec Smartpower 2.0 400 W supply for $44.99 after rebate.

Hope that helps.