Power Supply DOA

[sgs]

Just started first PC build. Screwed in Antec 550 TruePower to case, connected
case fan to standard 4 pin peripheral outlet on psu (not fan only outlet),
plugged in the psu and turned it on (black switch from 0 to 1). I noticed that
the case fan is not running. Then I noticed that neither of the 2 fans built
into the psu are running.

Does this automatically mean that the psu is DOA? Is it possible that simply
screwing the psu into the case has created a short. Does the motherboard need
to be connected to the psu for the psu's internal fans to be running? What is
the easiest way to test if the psu is DOA?

[mrrobotto]

You have to have the psu connected to the mobo. The mobo turns on the psu.

[Midknyte]

you can buy a PS tester.

[Sterling_Aug]

Like mrrobotto said, ATX power supplies will not turn on unless they are connected to a load (the mobo is the only load that works).

[Midknyte]

http://www.compgeeks.com/details.asp?invtid=ATX-PT

[aaeryhn]

I had the same problem just days ago. Turned out to be a grounding issue with my motherboard. Might try taking the mobo out of the case and testing it with the power supply to rule out grounding. Kudos to mrrobotto for pointing it out to me the first time

[rangeral]

Is the cpu fan plugged into fan header 1 as well?

[stix_kua]

Originally posted by sgs
Just started first PC build. Screwed in Antec 550 TruePower to case, connected
case fan to standard 4 pin peripheral outlet on psu (not fan only outlet),
plugged in the psu and turned it on (black switch from 0 to 1). I noticed that
the case fan is not running. Then I noticed that neither of the 2 fans built
into the psu are running.

Does this automatically mean that the psu is DOA? Is it possible that simply
screwing the psu into the case has created a short. Does the motherboard need
to be connected to the psu for the psu's internal fans to be running? What is
the easiest way to test if the psu is DOA?

According to what you have sated, you never pushed the power button on the front of the case...the vacation switch on the back allows for the power switch on the front to power on the computer. That switch is like the box in your wall for your outlets you should try to use it to turn devices on and off...leave it on unless your are repairing your PC.

[lptech]

sgs-

You need to have the PSU connected to a load (motherboard) or it won't start. If the PSU is connected to the motherboard and you tried to start it by momentarily grounding the two pins that is labeled PWR on the motherboard check for a grounding problem. Maybe there are stand-offs that are touching the bottom of the motherboard which you can't see!

Remember that (1) you must have a load in order for the PSU to be activated, (2) must check for a grounding problem and (3) you might have a motherboard that requires that you have the fan headers connected to the Heatsink Fan or Fan in order for it to work (part of feature on some motherboards to prevent you from accidentally frying out the CPU)!

If you've checked for the above, then most likely it is a failed PSU that's the culprit! You have to always test things out methodically to rule out all the other possible causes. Good luck!

LPTECH

[Hearie]

Originally posted by Sterling_Aug
Like mrrobotto said, ATX power supplies will not turn on unless they are connected to a load (the mobo is the only load that works).

Sterling - Did you forget about the PSU Testers? They also provide a "load" for the PSU to start. Not being picky here, just figured you fergot about that.

[mrrobotto]

Originally posted by sgs
Does the motherboard need
to be connected to the psu for the psu's internal fans to be running?

Sounds like he doesn't have the psu connected to the mobo by his statement. Why buy a psu tester if this is the case? I guess it depends on how you interpret his statement.

[ukulele]

Here is a link to help you test a psu without a psu tester.

All you need is a volt meter and a piece of wire.