Power Supply Testing Help Please!

[wacki]

I have an ASUS A7N8X Deluxe, and a 450 watt power supply that came with a chieftec (alienware style) case i bought at newegg. The problem is ASUS probe is telling my that my voltages are going way off. My 12V is occasionally falls to 3 volts and my 3 volt falls to 0.8 volts!
I have a multimeter and I want to test the power supply, but how do I activate the power supply when its not plugged into the mobo? The reason I want to test the power is because I don't know what is actually going wrong. How do I tell if the houshold current is bad (not likely but anything is possible), the powersupply is bad, or the mobo probe is going bad?

Thanks for any advice you can give

 

[Jesta]

Put a paperclip or a small jumper wire between the green and black wires on the ATX plug. The power supply will then turn on so you can test voltages but I am almost certain that your voltages will not the the same as hooked to the board because there will be no load. Hope this helps.

 

[DannyBoy]

My A7N8X Deluxe does this too, I was looking around tonight and it seems like its not an un-common thing, it also seems like its nothing to worry about.

If you still want to test it, like was said the voltages will probably not be the same because of no load.

I would be interested to see what your results who you though...

 

[VansTheMan]

Is your system running fine? Anything weird happening? BIOS up to date? Try doing what Jesta said and see what voltages you get. If your meter has small enough probes, you can do this: Take your mobo out of your case and put it on a piece of cardboard or something else non-conductive. Plug in the ATX connector and boot the system then probe the different rails. If we don't hear from you for a couple days, we'll assume you have electrocuted yourself and I'll dispatch a medic to your house. Disclaimer: Only try this if you really know what you're doing because if you short something, you could fry your board and that would make us all sad.

 

[wacki]

Thanks for the help, I'm going to try and test it.

If I could find some lightbulbs that work of of 3 - 12 Volts I think I could easily simulate a heavy load. Thats only, if I have the time to mess with it tho. Right now I think I'm just going to buy the Fortron power supply that won anandtech's editors choice award in their review.

P.S. DannyBoy if u have the same problem I do, what kind of psu do u have?

 

[Jiggz]

If the voltmeter probes are too big use paper clips wrapped around the probe. Make sure you wrap it (probe and clip except for the tip)again with electrical tape to make sure it does not fall off the probe and at the same time prevent short circuit the PSU.

 

[randypj]

VansTheMan--My Dad did something like that when his system was sometimes not showing all drives on bootup. I think he had 4 drives, and was running RAID, plus a couple burners. He found that the PS was getting a tremendous hit when the drives powered up. His cure was a better and higher wattage PS.
--Randy