A neighbor asked me to look at her computer that wouldn't turn on. Prior to leaving on a couple week trip she unplugged her computer. When she returned, she plugged the cable in again and the computer wouldn't turn on.

I tried swapping power cables with the monitor and no effect, the cable is good. I also popped off the case and the power light on the motherboard was on. I manually bridged the power switch pins and nothing happened.

I'm going to take another power supply over there tomorrow and see if that's the problem, but otherwsie does anybody have anything else to try/test?

Thanks

I'm no computer guru, but I my machine is from hell, and has experienced every hardware failure under the sun. My CPU and video card both caused such problems (when it wasn't my mother board or power supply). Try testing both those, if possible.

Aliens must be preparing for the invasion, becuase I woke up with the exact same problem....

Simple case of GDI using their EMP weapons against us.

Try jumping the green wire on the motherboard molex.

http://www.overclock.net/faqs/96712-how-jump-start-power-supply-psu.html

This kind of issue is almost always the PSU.

Out of curiosity though, does she use dialup? She probably would have left her phone line connected, and I've seen lightning kill modems but leave the rest of the system unharmed (though the bad modem prevents the system from turning on).

Anyway, it's probably the PSU.

Thanks for the guide on manually starting the PSU, I was going to look for one of those.

And to Aglar, she does use dialup, I assume the line was left in, and we had several lightning storms in the past couple of weeks.

Thanks for the tips, I'll get back to you tomorrow on what happened.

That being the case, I'd say there's a good chance that the modem could be the culprit. If the PSU thing doesn't work out, try pulling the modem.

Good tip about the modem, Aglar. If the modem is fried, the phone cable will almost always need replaced too. I've seen this happen a few times.

Good point, thanks.

I would test either the power supply like you mentioned or possibly the mother board... although it's likely she just fried the power supply.

But he was being nice...
What did mechwarrior ever do that was so bad as to get permabanned?

Alright, I tried several things and here are the results:

I was able to manually power up her PSU with the paperclip trick. I multimetered a few things and the voltages were good.

I stuck a different power supply in there and it wouldn't boot.

I confirmed the computer's power switch is good with the multimeter.

I tried removing the modem and seeing if it'd boot.

I plugged the power connector from the original PSU into the mother board and bridged the pins from the top to start the machine, the fans start and the drives click, but we never see anything on the monitor. Removing the paperclip kills the machine. When I do this, the power lights on the front of the machine don't light.

Next time I'll take another videocard to test with, but other than that I'm out of ideas. I find it very odd that I have to keep the pins manually bridged to keep the computer running, that makes me think there a more engrained problems with the power system/motherboard.

Ideas?

Uh oh. Motherboard methinks.

Funny you should say that, I just came here to post this:

Now that I've got the model number (eMachines T3624), I've done a bit of searching and this problem is not unheard of. Same symptoms, PSU seems to work, even replacement, turn on the computer, nothing. The consensus seems to be that the crappy PSUs have a tendancy to take out the motherboards.

Any good definitive ways to show the motherboard is bad (either directly or by exclusion)? I'm pretty much convinced this is the case, but I'd like to have something a little more credible to stand on then "I read it on the internet".

Basically all you can do is replace every component required to boot (CPU, RAM, video card). If it boots, the motherboard is fine and one of those components is faulty. If it doesn't, motherboard is bad. Or replace the motherboard. I don't know of any other way to determine if it's failed.

Just for fun, are the tops of any of the capacitors on the mobo bulging or leaking? There was a massive shipment of bad capacitors a few years ago that found their way into motherboards (and other electronics), it's possible that this could be the problem with the mobo.

This is what a bad capacitor looks like (a good one would have a perfectly flat top):

I'll take a look at the capacitors and see if anything is way out of place. Her warranty expired a couple of months ago and it looks like it'll be about $110 to replace the motherboard on a $300+something original price.

She also mentioned it was slow, and I looking at the specs I can see why. Celeron with 256kb cache, 256 mb of RAM, 64 of which is devoted to the video card, leaving 192 to run XP. I might just take this oppertunity to convince her to get a new machine.

New machine is a good idea...

Yeah, not worth saving IMO.

Take the opportunity to have her buy YOU a new PC and you can slip her your old one.

Or just buy her a new PC and switch cases.