Gigabyte 81875 No POST with new PSU

[ian_r_l]

Hi

I have a Gigabyte 81875 motherboard with a 3.2 GHz P4 CPU. My old PSU died one night so I replaced it with a Thermaltake Purepower 560w PSU. The new PSU does not start up for more than a fraction of a second before it goes into safe lockout mode. I disconnected everything apart from the ATX main connector and the ATX 12v P4 connector and still no joy. However, if I disconnect the ATX 12V P4 connector the PSU springs into life and I get a healthy 12v on both pins of the ATX12V connector. I have also tried reconnecting all the drives and re-inserted all the PCI/AGP boards but leaving the ATX12V disconnected and everything still works (apart from the PC not booting). I cannot see any visible damage to any components on the motherboard but do these symptoms still indicate a bad Voltage Regulator Module on the motherboard? or a bad PSU?

Many thanks

Ian

[kc8adu]

you have a shorted vrm fet.
hopefully it didnt kill the cpu!
if it is in warrenty rma it.
if not tc or i may be able to save it.

[ian_r_l]

Cheers for the speedy reply.
You have confirmed my own thoughts on the problem. The mobo is only 5 days out of warranty so I'm going to kick up a big fuss if they don't rma it.
I really hope it didn't cook the cpu too!

Ian