Discussion on:

Power-supply troubleshooting with a multimeter

Good testing tips for a power supply. I have only
one item to add. After verifying that the DC levels are the right value, re-check each pin checked before, with the multimeter adjusted for
AC volts, not DC. And of course, the proper range.
Whatthis does: the multimeter is now looking for
AC voltage, and there shouldn't be any (or very
little). 25- 50 millivolts is ok, but more than this will cause the digital circuits of the computer to work erratically.

One really important and common fault over looked in the article is to consider that the power supply is no longer correctly regulating the output voltages. We have seen many supplies where, if you measure the DC voltages they are pretty close, buttheres 2 or 3v ripple on top. This wrecks havock with most systems and causes some pretty bizzare stability problems. Moto - always check for ac ripple or noise on the power rails!

I have a question, for the article author or anyone else who knows the answer.
It is my understanding that since PC power supplies are switching, they won't operate without a load. Therefore if a motherboard is dead and not drawing any amps, will an otherwise good power supply's fan spin up when connected to it? If not, what would be a good way in that situation to determine whether the problem is the power supply vs. the motherboard? Would attaching a couple of drives help, since they would draw amps?
Best wishes,
Faithe Wempen

Found this article while searching for PSU testing
methods, it was very informative and to the point
I will be adding this site to my favs.

My computer doesn't power up when pushing the power button on my computer, meaning nothing happens at all. According to the article pin 9 is suppose to have 5vdc when ever it is connected to the mother board. My power supply is only producing 2.2 vdc at that pin. So is it safe to assume that I have a bad power supply or could is still be something else?

very helpful .Photos helps a lot.

this articl does not tell me how to check whether mobo or power supply is problem only if I get voltage at pins

you can actually buy a power supply tester for less than $15 that will do the job. handy, especially if you build or work on your own pc. just search for power supply tester on newegg or amazon.

With these voltage tests you are only testing under a static condition, once a load is applied to the Power Supply those voltages could drop sharply due to it's inability to supply the necessary Wattage required.

my machine is hanged during my work. Is there any supply problem in my machine then suggest me any good suggestion?

when i work on my site istqbsoftwaretesting.blogspot. com my system get hanged and i lost my all data due to restarting problem. So please suggest me the solution as soon as possible.

nice checking tips for a long power supply, I have also experienced checking like this, you are truly right. Thanks.
http://www.memoryclearance.com/catalogsearch/result/?q=406393-001+&x=0&y=0

This power supply repair guide can help any one that have smps power supply problems.
http://smpstroubleshooting.com/