Hi

I have got ASUS Motherborad P5e,,,,yesterday it did POST today it did not work.

I can see SB LED lights up in green color

I removed all cards and RAMs and HD,,,,only CPU left, and shorted the pin for POWER SW,,,still noting worked, CPU fan wouldn't spin at all.

Unplugged the power supply cable that is hooked to motherboard and hooked it again

If the motherboard SB LED lights up, the power supply is almost certainly working.

Another test I did try this power supply on my old PCs (i.e another motherboard) and its fan and the CPU fan both of them span.

PSU is BESTA PT-550W

Is there any other troubleshooting should I consider ?

Thanks

Plug a speaker in to the motherboard header if thier isnt one already do you get an POST beeps?

Sounds like your motherboard failed. The LED on the board is a standby LED (if I understand your description) and requires next to no voltage to fire. It's not a good place to start when you're troubleshooting.