Do this at your own risk...
Assuming that you have a standard ATX power supply (some DELL's dont !)
Is the power cord plugged into the power supply?
Is the surge protector on?
Is it plugged into a live outlet?
Plug the power supply AC power cord directly into a wall outlet.
Many recent ATX power supplies have an additional power switch
on the back of the power supply itself. Is it on?
Is the power supply set for the correct voltage?
Most of them have 110/220 Volt switch.
The 220 volt setting won't work in the U.S.A. The 110 volt setting in Norway, for example, will probably fry the power supply--I've done it!
Unplug the power cable to the power supply and disconnect all of the power cables
from the power supply except the main power connector to the motherboard.
Disconnect all other cables to the motherboard except the front panel power-on connector.
Remove all expansion boards from the computer.
Push the power-on switch and see if the power supply fan turns.
Try another outlet.
Now to answer the question...
Unplug the power cord from the power supply,short-out pins 14 and 15
on the power supply main power connector, and plug-in the power cord
just long enough to see if the fan is working.
This may not be the best thing to repeatedly do to an ATX power supply (it can damage it).
The ATX12V Power Supply Design Guide states that the power-on function should be normally
done with TTL (transistor transistor logic) circuitry which pulls pin 14 low.
I use a jumper cable with alligator clips at each end with partially stretched-out
paper clips in each alligator clip (an old trick).
Pull the power plug before removing the jumper.
If the power supply works, remove the motherboard and see if it is shorted-out by a stand-off or lose screw.
I have seen cases where a particular "good" ATX power supply would not work with a
particular "good" motherboard--so much for standards and design guides.
literally freeze; but the screen still shows up.
Linear Mode
