Dead motherboard?

[T. R. Oglodyte Moderator Find all posts View Profile Close T. R. Oglodyte]

Also posted OY - looking for a quick answer!! DW is anxious.

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Computer does not boot at all - nothing no BIOS, nothing.

If I completely disconnect the power supply, and let it sit, upon start-up a blue LED that normally lights up during boot, flickers once then shuts off. Also the fan will twitch, then nothing.

I've tested the motherboard power supply using a multi-tester and the pins on the main motherboard power supply (20-pin ATX connector) are in spec, including the PWR_OK pin.

I can't do load testing of the other connectors because I'm not getting load to the motherboard.

At this point I can't think of anything else except that MB is down for the count. Anybody else have any suggestions?

[bnoble Senior Member Find all posts View Profile Close bnoble]

Leave it unplugged, and hold the power button for fifteen seconds. Then plug it in and start it. It doesn't always help, but it helps surprisingly often.

[billymach4 Super Moderator Find all posts View Profile Close billymach4]

Are you 100% sure it not the Main Power Supply?

[T. R. Oglodyte Moderator Find all posts View Profile Close T. R. Oglodyte]

Are you 100% sure it not the Main Power Supply?

All of the voltages at the ATX are on spec.

Added observations:

Possibly a bad connection somewhere on the motherboard. If I try to power on, then work the ATX connector to verify the connection is tight, the same flickering and fan twitching as described above will sometimes happen.

My second post above was done with optical and hard drive disconnected, but the video card was installed.

Next I removed the video card. Initially this was the same behavior as before, but this time when I made the ATX connector was tight, the fan started operating and the motherboard went through boot to the point where it beeped. Pushing the power switch then caused it to shut down immediately. Pushing the power switch did not do anything until I again made sure the ATX was frimly connected; then it would sometimes flicker and other times commence boot.

If I put the video card back in, then the fan never starts up. It seems that the added load of the video card takes more power than is being delivered to the motherboard through the ATX.

Trying to make sense of it all, it seems to me that I have a bad connection somewhere on the motherboard, most likely at the ATX connector. Sometimes it doesn't connect at all, and other times when it does connect the connection isn't good enough to get the power to do much more than operate the mother board.

If the problem were back at the power supply, I don't see why working the ATX connector would cause any change in performance. It seems to me that the problem most likely is at the connector or downstream.

And if the problem were the video card, then it should function totally normally with the video card removed. But it doesn't, though installation of the video card doesn't cause it to boot at all.

[bigfrank Administrator Find all posts View Profile Close bigfrank]

I had my wifes computer that did the same thing and it turned out to be the hard drive.

[T. R. Oglodyte Moderator Find all posts View Profile Close T. R. Oglodyte]

Well, with the video card removed and running the monitor through the VGA it's working normally.

At this point I don't know if the video card itself that is the problem or if there is a weak ATX connection and the added load from the video exceeds what the ATX connection will provide. I suppose it's possible the power supply itself is faulty, and not providing the power, but that seems less likely with the issues I noted by working the connector.

Hard drive is working normally.

[billymach4 Super Moderator Find all posts View Profile Close billymach4]

Steve what is the capacity of the power supply? Power supply is easy to R&R. I would swap it out with a more powerful unit. Add back the Video card and take it for a ride.

Then you can rule out the power supply vs the MB. Power supply is cheaper than a new MB. If nothing else you will end up with a spare PS. A spare PS is always a good thing.

[bigfrank Administrator Find all posts View Profile Close bigfrank]

You know what is funny, In the last 2 years I have had 2 hard drives fail 1 monitor 1 power supply 1 video card, Now if you add a year more then add 1 more hard drive and a mother board due from a short from the usb hub. We do have 4 Computers in the house my son has 2 of them which are lighting fast and he built 1 from scratch.

[T. R. Oglodyte Moderator Find all posts View Profile Close T. R. Oglodyte]

Steve what is the capacity of the power supply? Power supply is easy to R&R. I would swap it out with a more powerful unit. Add back the Video card and take it for a ride.

Then you can rule out the power supply vs the MB. Power supply is cheaper than a new MB. If nothing else you will end up with a spare PS. A spare PS is always a good thing.

220 watt. The whole system is an off the shelf Acer unit, operating with no problem for almost two years.

[mas Senior Member Find all posts View Profile Close mas]

For my money, I would follow Billymach's suggestion. I've run into PS problems before that mimic what you describe and 220 watts is definitely on the small side as supplies go. It could be that the PS is aging and not able to support the load.

[bigfrank Administrator Find all posts View Profile Close bigfrank]

220 watts sounds very under powered, My old dell had 400 watts and and that was more than 6 years ago

[WanderLust Senior Member Find all posts View Profile Close WanderLust]

I'm surprised

that no one has suggested the obvious answer!!!!

Longer cables!!!!!!

I do feel your pain and hope this helps in some small way.

[T. R. Oglodyte Moderator Find all posts View Profile Close T. R. Oglodyte]

Steve what is the capacity of the power supply? Power supply is easy to R&R. I would swap it out with a more powerful unit. Add back the Video card and take it for a ride.

Then you can rule out the power supply vs the MB. Power supply is cheaper than a new MB. If nothing else you will end up with a spare PS. A spare PS is always a good thing.

For my money, I would follow Billymach's suggestion. I've run into PS problems before that mimic what you describe and 220 watts is definitely on the small side as supplies go. It could be that the PS is aging and not able to support the load.

220 watts sounds very under powered, My old dell had 400 watts and and that was more than 6 years ago

Next time I'm heading in the direction of Fry's I might stop in and see if they've got something that will work.

The ATX on my motherboard is 20-pin; I suspect that's going to reduce my PS options.