Repeated Power Failure

suddentwigs

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Jan 27, 2010
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Hi there. I have been using my homebuilt system based on the Gigabyte HA55M-USB3 for five years now. Yesterday I took it apart as I sometimes do to remove dust and clean the inside. I took precautions such as using an antistatic mat, and as far as I could tell, no harm came to any of the components. However, when I put it back together again, it refused to boot properly and has done since. What happens is the computer starts as normal, but after a few seconds the power cuts. The amount of time before this happens varies, but nothing ever appears on the screen. The fans are functional, but cut along with the rest of the power. My external hard drive comes on when I switch the rocker switch at the back, and continues when the rest of the power cuts, so I know it isn't the power supply. The light on the front power switch comes on when pressed, but switches off when the power cuts. The Hard Drive indicator light for the internal hard drive does not light. Is this problem familiar to anyone? Short of replacing components, it is hard to know where to start.
 
I remove the computer's innards and vacuum the inside of the case. As for the components, I mainly just inpect them, blow on them and wipe off any dust gently with a duster. Usually doesn't cause a problem! PSU is the Earthwatts EA-500D.
 
Check the jumpers, especially the cmos jumper usually in the lower right corner somewhere, it should be firmly on pins 1+2. Also check the seating of all the connectors, 20+4 and eps, make sure the wires are firmly down into the connector and didn't push loose when reattached.

I prefer a 1/2" long soft bristle paintbrush to a duster, and use the vac to clean up the air as I 'paint' the dust. But thats me.
 
I have now tried cleaning inside my power supply, and when that didn't work, I tried it with a new power supply. Still no luck. I am fuzzy on the jumpers - The pins are bare, and presumably always have been. Could this be the problem? What can I do to try and fix this? I don't know anything about jumpers at all, what do they do? I know it's some sort of reset function on the motherboard; could this be useful to me?
 
At the 3 pins for the cmos reset should be a tiny square piece of usually black plastic with a metal inside. This slides over the 1st and 2nd pins from left. Without this jumper the bios won't work, so the pc will stop at boot. The 3rd pin should be bare, as this is the reset pin and when the jumper is moved temporarily to 2+3, resets your bios to the factory defaults as specified by the cpu. It's a must have piece of plastic on 1+2. And yes they come off quite easily, so when you said you cleaned, and the results, it was my first guess.
 
Very interesting! I only have two pins, which seems unusual. Nonetheless I imagine they should be covered. Presumably I can buy a replacement at a component store? If this works, I will be a VERY happy man.
 
Okay ... so I bought some jumpers and put one on the two pins, and switched it on at the back. Then I switched the front power button, and this time nothing at all happened. When I removed the jumper, it got a burst of power and immediately switched off. When I tried the front button, it did nothing until I had switched it off and on again at the back. Most confused!
 
Ok, after looking at more than a few boards to find an answer, yes you have just 2 pin cmos reset, and yes they are supposed to be bare as far as I can tell, kind of redundant I think, having no jumper readily available would make resets an interesting problem. So that's good.

The fact you hit the board with a duster is really starting to worry me. Most dusters work by making the dust cling to it via electro-static charge, which inconveniently is the absolute worst thing you can stick inside any electronics device.

Since you have already tried using a different psu, and I'm assuming it was a known working unit, something else you could try is the power switch short. Your symptoms are about identical to what happened to my old dell when the switch died. If you look at the very bottom right of the mobo, you'll see a bunch of small wires plugged onto pins, one of which will be labeled PWR and is usually a red and black pair of wires (+ and -). Using a paperclip or small flathead screwdriver, momentarily short those pins, for about the same amount of time you'd hold the power button normally. See if that works. Trying to think of options other than 'mobo is fried'
 
I tried shorting the power pins, to no avail. For good measure, I then removed and returned the battery after 1 min just in case it had any effect. The effect it has had is to make the bursts of power even shorter! It now just flashes on for a split second before failing, and repeats that until I switch it off at the back. Starting to feel as though the duster is responsible, which is most frustrating since it is such a seemingly innocuous thing. Is there anything that can be done to sort it? In what way does the static charge ruin the motherboard, and why did my antistatic mat not help? I suppose when I dusted I probably was holding it in my hands rather than on the mat. If I need to replace the board, what are my chances of getting one that works with Linux and is compatible with my existing components. I really don't want to shell for a new everything! My current board is Socket 1156.
 
The duster carries an ionized charge in the head itself, it creates it's own charge the same way you create static electricity, movement. The duster handle itself isn't a conductor, more an insulator, so any built up charge stays on the head and sucks up the dust, without grounding out with you holding the handle. If you figure that static electricity is basically tiny lightning, you'd not be far wrong. It doesn't carry a lot of amperage, but does carry a lot of voltage, way more than the 12v, 5v, 3.3v, -12v etc. and shorting that charge across the cmos chip and other sensitive components can have disastrous affects.
 
Having now gone through the five stages of grief (I skipped Bargaining, because how do you bargain with a computer?), I have decided to cut my losses and replace the motherboard. If that doesn't sort it I guess I'll try replacing the processor instead. Trouble with it being 5 years old, my options are limited as far as Socket 1156 goes. Thank you for all your help, regardless of the ugly truth.
 
Since you have decided on that course, and honestly I'm now at a loss for any further useful info, you having done any steps I would have suggested, I will say this. Cpus are for the most part pretty durable, suffering mostly from bent pins. If however you have any thoughts that there is a strong possibility the cpu is toast, you should look into maybe replacing both cpu and mobo as trying to find an 1156 board and possibly a 1156 cpu could be a daunting challenge.