G
Guest
wire?
The black wires aren't hot because they're all grounds, and the green
wire is the Power_On signal, an input, which is designed to accept
anything from 0-5V. The power supply's main voltages (+3.3V, +12V, and
the +5V on the red wires) turn on only while the green wire is at about
0V (you can't simply blip this wire to a black wire but must leave it
connected, unlike the power button on the front of the computer).
There's no shock hazard because the highest voltage from the supply is
just 24V, obtained by connecting the blue -12V wire to a yellow +12V
wire, but it's possible to damage the Power_On signal by connecting it
to a negative voltage (blue or white wire) or too high a voltage
(yellow +12V). Also a poorly made power supply can be ruined by
shorting the wrong wires together, such as one of the voltage wires to
ground (a properly made one will simply shut off and be reset by
unplugging its AC cord for a minute). You can minimize the chance of
damage by sustituting an approximately 200-500 ohm resistor for the
paperclip. I normally use a 1/4 - 1/2 watt resistor because that's
what I have handy, but to be 100% proper the 200 ohm should be rated
for at least 5W, the 500 ohm for at least 3W, to handle the worst-case
scenario of the resistor being connected to the +12V and -12V.
Most alligator clips can't reach the metal contacts of the motherboard
power connector