Please help me frankenstein my machine (yes, that's used as a verb).

November 30, 2005 4:21 PM

Help! My computer won't power up!

So I bought the PC about 9 months ago from a guy who built it himself. It was in an old--really old and big--tower at the time so he replaced the case with a new one (tho kind of a cheap-o model). I knew I was taking a chance with this purchase, and here I am now paying the price for that. Murphy's Law, I suppose...

Anyway, one quirk the comp. has had from the beginning is powering up. If I shut it down, when I go to turn it on again it won't boot up. So through trial and error I figured out a trick, a trick my computer geek friends who haven't seen it, don't believe it--I unplug the PC from the power strip, then plug it back in. Turn on the power and Voila! It boots.

Until yesterday, that is. Now it won't power up, at all. I've tried everything short of Voodoo dolls to no avail. A friend suggested that it could be either the power supply (which came with the tower) or the motherboard itself, and one of them will need to be replaced.

Anyone have this happen to you? Obviously I'd like to fix it myself and avoid outrageous charges at a PC shop somewhere, but my putting-hardware-in-the-right-place skills are pretty basic.

posted by zardoz to Computers & Internet (15 answers total)

Bad power supply. My bet, but not sure.
posted by Ethereal Bligh at 4:24 PM on November 30, 2005

I would bet a bunch it's the power supply, from the sound of it it's been trouble since the start, new ones are cheap and easy to install.

You might want to get new geek friends too, unplugging the power supply to let it reset (you can usually hear it 'click' if you put your ear up close) is pretty standard troubleshooting.
posted by Cosine at 4:26 PM on November 30, 2005

My first guess is the power supply as well.

Don't worry, it's a very easy fix. I had my first one go bad a several years ago. As of that time, I had never even opened a PC before. I was able to replace the dead power supply without a hitch. Go slow, follow directions, you'll have no problems.
posted by bawanaal at 4:33 PM on November 30, 2005

Try *uprating* the power supply from 3 to 400w while you're at it - might be a drain if you only have a 3/350
posted by DrtyBlvd at 4:35 PM on November 30, 2005

I agree that it is probably the power supply, but there is an off chance that an expansion card has fried. (sometimes, a bad expansion card will keep the system from starting...unplugging/replugging as you described may be jiggling a connection enough to get it to work).

Try removing all of the PCI cards from the machine that you can (i.e. modem, NIC, soundcard, etc) and see if it boots.

Like I said, I would bet that its the powersupply, but it cant hurt to take the cards out and check.
posted by stupidcomputernickname at 4:47 PM on November 30, 2005

My brother had the same symptoms (with the same workaround) and eventually ran into the same problem - the workaround quit working around. I examined his motherboard and found that more than half of the capacitors had gone bad. Look at the big, round, can-shaped things on the board - if the silver tops are bulgy instead of flat, or if they have brown gunk leaking out the top, you may be in the same boat. This is a common problem with some boards.

As far as a fix, I recommended he replace the motherboard, since it's out of warranty - if you have the same problem, there may not be much else you can do. Do consider the power supply, too, though.
posted by pocams at 5:46 PM on November 30, 2005

Another trick is to uplug the power connector to the motherboard for a half minute, plug it back in, and try to reboot. I don't know why this is different from unplugging the case but it has worked for me sometimes.
posted by rdr at 5:52 PM on November 30, 2005

I don't think it's the power supply. Modern systems never really power down--there's always some trickle charge for instant boot-up from LAN, for example, and it sounds like when you unplug the power supply, you reset whatever it is that's screwy. I believe the problem is with your motherboard. Could be bad caps, as pocams mentions, but it's a relatively cheap fix if it's an older system. There are a few dealers that sell older equipment, just off the top of my head: Retrobox.
posted by Civil_Disobedient at 5:55 PM on November 30, 2005

I disagree with C_D, but I just recently figured out that a long-time problem I had with a motherboard was a bad capacitor. Here's a photo:



That board was out of warranty, but I contacted the manufacturer anyway and they offered to fix it for $17, including the shipping back to me.
posted by Ethereal Bligh at 6:30 PM on November 30, 2005

Old timers (like me) may remember the old "reset the ATX power supply" trick, which goes as follows:

1) Hold in the power button on the case whilst simultaneously unplugging the power cord from the case.

2) While still holding in the power button, wait five seconds, then plug the cord back into the case.

3) Release the power button.

At this point, another press or two of the power button should result in the computer powering up.

I don't remember if this was specific to certain brands or not. It's been a while.
posted by mr_crash_davis at 7:41 PM on November 30, 2005

One of my sister's systems had the bad cap problem... Somebody sold her a new power supply, and the system was 'fixed' for about a year before failing to power up again.

Your problem does sound like bad caps to me because of the unplugging trick you were using. I don't know exactly what the power-up logic is, but if the caps were leaking a little current then the power supply might think the motherboard never turned off... Also, the bad caps problem gets progressively worse, which sounds like the problem you are having.
posted by Chuckles at 8:04 PM on November 30, 2005

"Your problem does sound like bad caps to me because of the unplugging trick you were using."

That's a good point. BTW, the story behind all those bad capacitors in motherboards is a good one. Wasn't it something like a typo in the "recipe" and that one supplier provides the capacitors for all the Asian motherboard manufacturers? Something like that.
posted by Ethereal Bligh at 8:42 PM on November 30, 2005

Other than the fact that I have had at least three boards with the problem, I don't really know anything about it myself. The site I always link to is badcaps.net:

How did this happen?

The reason this problem exists is because of a large-scale industrial espionage foul-up. Some companies decided to steal an electrolyte formula from another competitor. Little be known to them, the stolen formula was incomplete and flawed.

It is pretty funny! In a not very funny kind of way...
posted by Chuckles at 9:06 PM on November 30, 2005

Found the wikipedia page on it: Capacitor plague. It is starting to sound very ugly!

The fact that these failure-prone capacitors are still being used has angered many people, especially in cases where a motherboard populated mainly with high quality capacitors has one or two of the bad capacitors on it, leading to accusations of planned obsolescence on the part of motherboard manufacturers. Indeed, a strong case can be made that these capacitors (which often fail in 6 months or less) are still being manufactured, and are still being chosen over superior components by manufacturers to use in their products.

posted by Chuckles at 9:16 PM on November 30, 2005

Response by poster: Great advice from everyone, thanks to you all! Now I'm going home to investigate more...wish me luck!
posted by zardoz at 11:33 PM on November 30, 2005