motherboard

A mainboard can't be tested with just a voltmeter. Period.

Hi DrKlahn

If the voltages at the connectors are within tolerance, you've done what is possible and it's time to swap the board out for one that works.
 

Ok,could you tell me the procedure for checking the connectors and tolerance

Thanks

Davy, what problem do you have, or what do you want to do ?

here a nice article about the motherboard components :  http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-The-Motherboard-Voltage-Regulator-Circuit/616

here the 24-pinn layout for ATX power supply :  http://pinouts.ru/Power/atxpower_pinout.shtml
there you can measure the voltages

As I already mentioned, a voltmeter is useless to diagnose a mainboard. The only thing you can measure is the Voltage at the socket where the power supply is plugged in. But you might as well measure voltage of the Power supply directly, not on the board. If the socket has broken off or is loose on the board, that should be visible to the eye and you wouldn't need a voltmeter for that. Just resolder the socket to the board if that is possible.

For diagnosing a board you'd need an oscilloscope and you'd also need the detailed circuit diagrams for the board, which won't be freely available as only the manufacturer has those.