How to test 6 pin power connector using a voltmeter

I have a dead HD 7850 that when is connected with the one pcie 6 pin connector it requires doesn't spin its fans and outputs no display. I plan to test the mosfets on the board even though nothing looks damaged on the board. However i first of all want to check that the six pin connector is working. How can i do this using a voltmeter??? Many thanks for reading any help appreciated very much.