Measuring the 12V Rail

[asicman]

For a dual 12V PSU, how do you know where the rails are split? I.E. I have a fan connector on the mobo open, and it has a +12V pin. There's also a 1394 connector on the mobo open, also with a +12V pin. I want to measure the rails while Prime95 is running with a DMM, but how do I know which rail I'm measuring, or even if I've measured both rails?

 

[JimPhelpsMI]

Hi, I would suggest measuring all molex connectors betwee the Black and Yellow wires. Half are connected to the same "Rail" in the PSU and the other half to the other "Rail". Any big differences in readings would indicate which is which. Jim