Is this power supply working?

My computer started turning off automatically every 5 seconds. I disconnected the power supply, shorted the switch contacts so it'd come on, then measured the voltages. Those rated at +12V read 12.08; that rated at -12 reads -11.62; that rated at 5.08 reads 5.13. An unidentified white reads 1.18; an unidentified gray reads 4.92. I suspect they're all within range, at least without serving a load. When they're plugged in they come up to rated voltage then drop to zero, then they come back up again.

Any idea what the white or gray wires are for? They connect to pins in the motherboard's jack.