Power supply question

  • Thread starter Thread starter Hank
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Hank

Hello everyone. Ok i was wondering what wires I need to connect an
alternative switch to my power supply and start it up. I tried
connecting one to the green and one to the black and I get the fan in
the back winding up and then it stops. any suggestions?
 
Hank said:
Hello everyone. Ok i was wondering what wires I need to connect an
alternative switch to my power supply and start it up. I tried
connecting one to the green and one to the black and I get the fan in
the back winding up and then it stops. any suggestions?
Click to expand...


I don't know what "green" wire you're referring to, but, generally, green is
GROUND. You need to find the LOAD and NEUTRAL wires for a switch.
 
Hank said:
Hello everyone. Ok i was wondering what wires I need to connect an
alternative switch to my power supply and start it up. I tried
connecting one to the green and one to the black and I get the fan in
the back winding up and then it stops. any suggestions?
Click to expand...

The PSU should run, as long as PS_ON# is connected to COM. And
that is probably the wires you're describing. Normally, the
motherboard grounds PS_ON#, any time it wants the power supply
to run.

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

If the power supply refuses to run after it has stopped like that,
and won't do anything until AC power has been removed, it could
be a problem detected internally in the power supply. A power supply
may "latch off", until +5VSB is disabled for a moment. And that
happens when you set the switch to "off" on the back of the supply.
"Latch off" is intended to prevent the machine from looping through
one failure after another.

When a power supply indicates a failure like that, don't "torture"
the thing by rapidly flipping the switch on the back of the supply.
One poster mentioned in a posting, that he "tried 50 times" to get
a PSU to run, until he got a puff of smoke. So when protection
circuits are triggered, there is no guarantee they'll protect
against the fault forever. If a couple of tries is not showing
an improvement in symptoms, it is time to try another supply.
Either that, or risk damage to whatever is connected to the
supply outputs.

Paul
 
nobody said:
You must think you are an electrician. Unfortunately your knowledge of
both a "power switch" and computer wiring is lacking.
Click to expand...


You must think you're a poncy poncy tosspot...

....and you're right!
 
Hank said:
i was wondering what wires I need to connect an alternative
switch to my power supply and start it up. I tried connecting
one to the green and one to the black and I get the fan in
the back winding up and then it stops. any suggestions?
Click to expand...

Some PSUs won't keep running unless there's enough of a load on at
least one of the voltage rails. Often a hard drive is enough for
this. It used to be that loading just the +5.0V rail with at least 1
amp was enough, but maybe newer PSUs instead need the load on the +12V
or +3.3V. I have some old PSUs that require both the +5.0V and +3.3V
to be loaded with at least a few amps each. For the +5.0V load,
connect it between any red wire and any black wire; for the +12V,
between yellow and black; and for +3.3V, between orange and black.
Ohms = volts/amps, but it's also important for the load's watt rating
to be high enough, or volts * amps (better at least double that to
keep the load resistor cool enough).
 
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