Question : Problem: HP Power Supply

I have a HP d5151.
Fairly sure the power supply is gone.  
When i turn it on the light on the front of it comes on but goes off straight away.  
When i have it took apart when the power still plugged in there is still a green light on the motherboard.  
Is it likely to be anything else other than the mother board?

Where could I source a new one in the UK?
Part Number: 375496-001
Spare: 376648-001

Answer : Problem: HP Power Supply

The green light on the motherboard only indicates that 5V standby power is available. The power supply may still be bad even with this indicator lit up as there are other voltage rails like the +12v that runs most of the components in the PC. Replacing the PSU would be the first thing to try.
UK sources for PSU
http://www.spares4it.co.uk/parts/376648-001

http://www.bluegoosesystems.co.uk/catalog/HP/NEW/376648001.html