> I have a volt meter. If I put one probe of the volt meter into the socket
> hole that goes to a red wire, and the other probe into the socket
> hole that
> goes to the adjacent black wire (and the same for the yellow wire and the
> adjacent black wire) will this give me the voltage readings that I want?
>
> I don't want to short circuit the power supply (which may be on its last
> legs), but I do want to test it before replacing it. Is this the correct
> procedure?
>
> If anyone has an "Oh my god!" reaction to what I propose to do, please let
> me know.

     What you wish to do is very common and does not enlist a "oh my god"
reaction! :) While you can indeed measure the voltage like that, I fear the
result won't be very useful. The kind of circuitry used in PC power supplies
doesn't work very well without any load, in fact I've seen some power
supplies show completely normal voltages without a load, but when you stick
something on them they fail. If possible, make you measurements with a few
current sucking devices on it, a couple HDs is good. The voltage between the
red and black wires should read 5V +/- 5% usually, the closer to 5 the
better. The voltage between yellow and black should read 12V. Unfortunately
this type of testing will not always lead to a definitive answer, the only
way to get that would be to use an oscilloscope with a variable load on
every supply voltage (today's power supplies also supply -5V, -12V and even
3.3V in some cases). Good luck, TTYL

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