Is there any way to tell if you have a bad power supply?

[Medellon]

I was putting my old computer back together and when I turned on the power, nothing happened. How can you tell if your power supply is bad? Should the fan be spinning even when the power supply is out of the computer and not connected to the motherboard? I don't have any equipment to test the wires or anything like that but I would appreciate any and all comments. I'm having a bad week, 2 computers not working in 3 days and I have no clue what is wrong with them.

 

[compudog]

Need some more info please. Is it an AT or ATX power supply? It's easy to tell. An AT power supply has (usually) 2 sets of connectors that attatch to the motherboard. An ATX p/s has a single connector with 2 rows of wires. An AT power supply's fan should spin when you turn on the power. An ATX p/s usually needs a signal from the mobo before it turns on, though it is always supplying power to the mobo when switch in back is on, (if it has one.)

 

[Medellon]

I have an ATX power supply. If my motherboard does not send a signal, does that mean it's fried? Thanks

 

[Bglad]

No, fans go on with the power supply when switched on by the motherboard. If the computer goes on, it is not to be concluded that the power supply is the problem. There is no way to test without a volt meter. Even then, you are not testing output with any load on it.

 

[compudog]

Double check all of your connections. Triple check them even. The fan in the p/s may or may not spin when you first turn on the switch in back. You could pick up another p/s and try it to see if it fires up your system. The p/s is cheaper than a motherboard. If it still behaves the same way with the new p/s then you can return it (ask wherever you get it from if they will accept a return.)

 

[larrymoencurly]

I recently read a Usenet post where the problem was caused by a bad switch (CompUSA changed his PS and mobo, didn't fix it, small computer shop did).

Have you tried briefly shorting the pair of jumpers where the switch connects to the mobo?

 

[gmrickards]

I would suggest getting a volt meter or multimeter. They are fairly inexpensive @ Radio Shack and probably other places. It is probably the easiest way.