power supply dead?

[Master of Reality]

I got up this morning and looked at my coputer to find it off. I checked the power cable and outlet and such and they all seem fine.

My power supply has made whirring noises and strange other sounds before (not within a week or two) so im thinking it may be it. I turned the power supply on and off and then hit the power button and sometimes i hear a click. I thought perhaps it could be a breaker in the power supply or something or the power supply trying to turn on.

Does anyone know any way i could test to make sure it is in fact the power supply that is the problem? I will probly go down to the local computer shop and see if they know and see how much a new power supply will cost.

...it doesnt matter much if i buy a power suply and its not the problem because i have 3 other comps that need a P/S

[Linux Frank]

The easiest and most effective way is to take a DMM and disconnect the power supply from the Motherboard (or any other power connection) and then plug the thing in and measure the output voltage at the conectors. You should have + and - 12v and +5v (I think that is all that is used) wrt Gnd. Depending on where you measure. You should disconnect all power connections when doing this, that way you eliminate a faulty device as being the problem.

I would check the fuse on your mains input, both at the plug (If Canada has fused plugs) and in the system. With modern systems the fuse is probably in the power supply, which will mean opening it up, be careful and don't do this whilst power is applied. you can remove it and measure the Ohms as final proof if you have a DMM. Of course you may not have a removable fuse, in which case you are stuffed for this part.

Alternately there is the mix n match effort. Turn off the system. Open up and disconnect the power supply connectors from everywhere. Plug in and turn on. If the power supply fan starts turning (assuming the fan hasn't failed) then the problem is possibly in other items. Plug each piece of equipment in individualy and see if it starts. CDROM, HD, MB, etc. You might have to test the MB first, and leave that on for testing everything else individually - this depends you'll have to experiment. If it fails when everything is plugged in but not otherwise then the problem will probably be a faulty PS (crowbarring, whatever).

Be very methodical and don't be afraid to repeat the run the exercise several times to prove your thoughts.

Hope this offers a start.

EDIT : For reference a basic good ATX type power supply should set you back about US$25 or less (but could easily climb to three figures if you want really fancy, ultra quiet running, higher power, low noise, etc.)

If you have no waranty issues I highly recommend opening up and looking around for fuses in the box, you would be amazed how many monitors and TVs and stereos I have saved by replacing a broken fuse. Just make sure you use one the same rating as the one you removed - THIS IS IMPORTANT unless you really understand electricity.

[Master of Reality]

I went through and 1 of the 14 computers in my house happened to use an ATX power supply so i temporarily stole it and it worked with my computer, which told me it was indeed a faulty power supply.

It was a fuse in the power supply that blew. Who solders fuses in place? I had to pry it out with a screwdriver (isnt that called "mechanical technique" or something (the right tool for the job)).

But i didnt have another fuse and i already bought another power supply (well.. "I" didnt, but someone did for me). So i am gonna look around for a fuse and then solder it in place and use that PSU on one of the new (for me) mobos i have laying around

all in all i suppose it turned out well and i didnt fry any hard drives and lose the report i had for my exam in english

[Linux Frank]

...It was a fuse in the power supply that blew. Who solders fuses in place? I had to pry it out with a screwdriver (isnt that called "mechanical technique" or something (the right tool for the job))...

Lots of companies do this. It is no accident that many fuses used are looking like resistors and capacitors. This can be justified because many places now use resettable fuses and the like, which require much better packaging and need to be soldered (when you have to be aware of your rising and falling edges this is important).

But I am convinced many companies are using solderable fuses that look like resistors and caps, so that people can't just fix their equipment with ease. These companies do not want you repairing your equipment, they want you buying new stuff. They price out old equipment as too expensive to repair, and force you into a new purchase. Personally I hate this forced and unnessecary upgrade. Thankfully I work for a company that uses a fax machine that was brought possibly second hand 14 YEARS ago, and a photcopier much the same, and we just repaired our telephone exchange that I was told is at least 16 years old, and has been obsolete for 10. I hate filling landfils with useful stuff, thrown out because it is old.

I am pleased you got your system working.