4 Apr
2003
4 Apr
'03
4:49 a.m.
I tried to test the power supply itself by plugging
it into the wall, flipping the switch to "on", and probing the leads
with a voltmeter. Nothing. But with this particular computer, you have
to have that switch on AND push the soft power-on button, either on the
front of the case or from the triangle key on the keyboard. So, is it
possible that the PSU is not dead, but that I am not getting anything
because the power-on signal's not being sent when it's not in the
computer? Not, not, not, not?
Also, most switchmode power supplies will not power up without a load of
some sort. For example, to test ATX power supplies outside of a computer I
connect an old HDD as a load and short the power-on line to GND. Same
principal applies to Mac power supplies except you short the power on line
to +5V (from memory, it's been a while so check before you short anything).