VX550 Voltage Problem

I'm upgrading my old PC. Have just purchased a VX550. I haven't received my new motherboard yet but I decided to swop out my old PSU now as I'm reusing my old case. My PC started up ok but when I looked at my Smart Guardian software it said the -12v was only at -3.7v. all the others were almost smack on the correct values. I rebooted to check in the BIOS. This showed the -12v to be o.k. but showed the -5v at -61.7v. I tried to boot it up again but it failed during the first windows screen. I couldn't get it to start again. I refitted the old PSU and now it runs o.k. The BIOS and Smart guardian show the voltages on the old PSU to be generally within the current ATX spec (+/- 5 or 10%) but occasionally it goes slightly beyond these limits but only slightly.

I gather software can be unreliable in measuring voltages, but as the 2 voltages above seem to be way out and the computer won't boot surely it must be faulty. From what information I can find on the web the 20 pin connector is still the same configuration so it should work o.k.

Should I send it back or is it just not compatible with my old system? I don't fancy trying it on my new motherboard or hard drive in case they get damaged.

Any advice appreciated.

it should fine. there is no more 5 volt ground so i would expect wrong readings.

best to test with a volt meter, your bios may not be ATX version friendly on the newer stuff.

if you really had an almost +4 volt 12v ground i dont think the PC would even boot.

Synthohol,

Thanks for your response. Yes there was no 5v wire. I checked with paper clip and volt meter and voltages were all o.k.

Installed with new motherboard and works with no probs.