Windows 7: Is my PSU bad?

Hi guys
I have recently been having problems with my computer
This morning I went downstairs to switch on my pc and nothing.
so I took the front panel of and took a look inside.
I also noticed that with the panel off and when I try to switch it on all of the fans power up but then power straight back down again.
HElP!
Ashley

Hello there, Ash.

Did you check all the wiring inside your Case?

How old is the PSU? do you have another PSU to test? maybe from a neighbor or a friend..

Unplug the video card ( If it has a power connector) and see if it powers up and beeps .. Or pull the drives , basically try to see if it will spin up with less a power demand on it

+1
Wiring and connections.
Check the power and reset switch pin connections.

Ash, I have attached a pictorial guide on testing your PSU disconnected. I urge you that if you are uncomfortable about doing this not to and if you are then follow the directions carefully. You could damage your PSU and also shock yourself. Do this at your own risk. This will allow you to power up the PSU with peripherals connected to see if it's the PSU or the mainboard. This option should only be done it you can't get a spare PSU to install.

modtown - article - Powering an ATX PSU Without a Motherboard - if it ain't broke - mod it!

I use that method to run my second power supply....it will eliminate a bad power good motherboard problem.....