Sounds like there is a short in the power supply
electronics to the frame ground.
Could be a wiring problem, a circuit board problem, a
transistor insulator problem or a screw fastener problem (oversized screw
head, too long, etc,)
My speculation is that the most likely cause is a mica
power transistor insulator wafer is either missing or otherwise not working as
designed for some reason and the case of the power transistor is directly
connected to the power supply's frame ground.
Use a large USPS Flat Rate Priority Mail box to send it
to me and I can find out for sure. And pay another $15 to have me ship
the repaired power supply back to you.
Thank you for this. I'm no electrical engineer, but I think I ran
the test you suggested.
set my meter to read DC volts.
turned the PS ON.
put the red meter lead on the red +13.8v DC screw terminal on the front of the
PS, and the black meter lead on the chassis ground screw. The meter read
-11.72v, not 0.
put the red meter lead on the black -13.8v DC screw terminal on the front of
the PS, and the black meter lead on the chassis ground screw. The meter
read -25.58v, not
So it looks as if I have a definite problem. I
don't see any obvious stray wires or
Could this be caused by a bad cap or two? Or am
I just wasting my time with this
I remember one member had warm cables back last year(?)
power supply +13.8 V DC lug was touching the power supply chassis.
think the current loop would be from
+13.8 V DC to chassis to
protective ground (green wire) to Desktop computer protective
The Desktop pc protective ground is connected to DC ground
DC ground wire connects CP3/4 and then to the negative
lug on 13.8V DC power supply completing the ground
With a DC voltmeter,
I would check voltage
from power supply chassis to it's negative 13.8 Volt lug at front
then chassis to positive lug on front of power supply.
Both should be 0 volts.
The member from last year saw
-13.8 volts from power supply chassis to negative lug on front of power
That means his +13.8 volt lug on front was shorted to
As always, I may be! wrong