Ok, so I have a PC and it has sat unplugged for maybe 5 months. I went to turn it on the other day and nothing. When I first plug in the power supply, the light on the back of the power supply comes on (small green LED) then goes out again after about 1/2 second. There is no fan or any indication at all that the computer is receiving power.

Could this be caused by the battery on the motherboard having died?

Any ideas?

What I have done:

-- Yes, the power cable is plugged in. Yes, electricity is flowing into the power supply.
-- I have opened the PC to check the connectivity with the mother board, power supply , etc.

I doubt it's the battery on the motherboard, you should at least hear the running. If I had to guess without seeing it, probably the power supply itself.

Thanks, Kandi.

Do they really just go bad like that out of the blue. It's a rhetorical question, of course, but it's pretty frustrating because there was nothing wrong with it just a few months ago..... Of course, the other thing is that computers are so cheap now, it's almost worth going to get a new one instead of investing the time and money into fixing an old one.

But still..... I'm hoping it is some expendable that can be replaced easily.

It is. It's probably the power supply. They're about $20.

There are two signs that is the power supply. The absence of these signs does NOT mean it's not the power supply...it's just confirmation.

1) Did you hear a sound like a gunshot when you turned it on? If yes, then power supply.

2) Did you see smoke coming from the back of your computer, toward the top of it? If so, then power supply.

If neither 1 nor 2 exist, it's probably still the power supply. It's the most overlooked component and arguably the most important when assembling a PC. It needs to be able to supply the right amount of power to all of the devices it's connected to (motherboard, hard drives, CD-ROM drives, etc.) and the more powerful these devices are, the more powerful the supply's going to need to be in return.

The PROBLEM is that most PC shops/manufacturers shortcut this part and put in a PS that weighs about as much as a feather and is grossly underbuilt for its purpose. Spend $30, $40, even $50 on something decent and you'll be well-served. (Here's a quick tip: pick it up and see how heavy it is. Good power supplies tend to be heavier as they're better-built and use more heavy-duty components.)

Now here's the good news: they're really easy to replace. A few screws on the back of your tower (usually one side of the tower and the power supply mounting screws), all the power wire connections, reconnect, and it either works or it doesn't. You're usually in and out in about 15-20 minutes (less if you're cool and don't put your side cover back on and let the components show. )

Thanks, Adam. I didn't see either of those symptoms that you described, but I don't doubt that you and Kandi have it exactly right. I really appreciate all the details you provided, including price and purchase recommendations. Maybe I'll get this fixed this weekend.

It's an old PC that I stopped using so much when I bought a new one. Recently the kids have shown a renewed interest in the computer and internet learning sites, so I wanted to fire up the older machine for their exclusive use.

Thanks again.

I read your post. But did you check the small rocker switch on the back of the PS. It is easy for one of those to get bumped to the off position in handling.

Also with the power cord disconnected use a toothpick or something to reach through the grill and spin the fan of the PS a few times. Believe it or not I have seen this work.

Originally Posted by colbyt

I read your post. But did you check the small rocker switch on the back of the PS. It is easy for one of those to get bumped to the off position in handling.

Also with the power cord disconnected use a toothpick or something to reach through the grill and spin the fan of the PS a few times. Believe it or not I have seen this work.

Thanks, Colby. I did make sure that the rocker switch is set to the correct setting... 120v. I didn't try to spin the fan, but I have read that having the fan spin is the one way you could tell that the problem was not the power supply. Unfortunately, I can see no fan activity, so there's another assurance that it likely is the culprit. Nevertheless, I will give your manual spin technique a try to see if it corrects the problem. But I'm getting pretty close to buying a new power supply.

Which begs the question, are all power supplies the same -- not quality which was talked about already -- but simply the in/out voltage, etc?

No. They're not. So you're going to have to do a bit of homework that way too.

The best thing you can do is to bring your old one in to a computer shop and say "this died. I'd like to replace it with something that doesn't suck."

Originally Posted by ADAM Web Design

No. They're not. So you're going to have to do a bit of homework that way too.

The best thing you can do is to bring your old one in to a computer shop and say "this died. I'd like to replace it with something that doesn't suck."

LOL!

Fantastic idea -- I will certainly take you up on that recommendation!

This can be helpful in determining what you need vs what was in there:
http://www.journeysystems.com/power_...calculator.php

Well, something like this happened recently with my power supply too.
It didn't work when I had installed the power supp. @ home. SO, I took it to the vendor, and voila it worked there. I'm still clueless as to why it worked there. He did nothing. I guesss you just need to see if the connections were removed before packing the computer.