No LED light on mobo

Asus A8v-e se motherboard
December 16, 2009 at 16:27:03
Specs: Windows XP
So one day before I left for school I checked something on my PC and turned the monitor off, a few hours I came back and noticed the computer had shut down.

Tried turning it on, didn't turn on, flicked the switch behind the PSU on/off, still didn't turn on. Then noticed the Green LED light on the Mobo wasn't on.

I installed a 500w PSU a few months(6-7 maybe) ago because of a failing one I had on this PC a year ago(was a 350w). It's been working flawlessly since now. I think?

The thing is, I'm not sure whether it's the PSU or the mobo that's gone this time. The weird thing is, that when my previous 350w PSU died, the Green LED light on my mobo was on, unlike now.

I really think it's my mobo, but I'd like some clarification. Is there any way I can test out my PSU or mobo to see which one is dead/fried?
BTW, I haven't tried to remove anything from my computer since I installed my 500w PSU.

Thanks for any help.

My PC specs:
Asus A8V-E SE motherboard
500 Watt Antec Powersupply
ATI HD x1950 Pro
AMD 3800+ X2 Dual Core Processor

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December 16, 2009 at 16:32:36
Do you still have the old PSU by chance? If so, connect it up to see if it feeds anything to the board like it did before. Poor mans method to determine if MBoard is the problem.

I wouldn't normally recommend connecting a bad PSU to your MBoard but it had been connected in the past and didn't seem to cause any other damage.

Good chance it is the PSU again. The brand and quality is more important than the rated wattage. Cheap PSU makers fudge the numbers.

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December 17, 2009 at 14:34:50
Ok, so I tried my old PSU(430W) and to my suprise, Green LED!!! But my computer didn't power on.

So, you guys think it's my current PSU(500W)? If the Green LED is still intact on the mobo does that mean it's still working?

BTW, tried it again with my 500W PSU and no Green LED.
Thanks for the advice OtheHill.

And If I should try another PSU, how many watts should I get and what would be a good brand?
The old 430W one is a ThermalIntake and the 500W one is Antec.

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December 17, 2009 at 15:09:03
Power supplies can quit completely or partially. The original quit partially. The current one appears to have died completely.

Antec is a good brand and without specs of your computer I can't say for sure but either you are overloading the PSU or there may be something wrong with the AC current in your house. Two power supplies dead makes me wonder.

Another possibility could be overheating. That will kill even a good PSU eventually.

What are the specs of your computer?

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December 17, 2009 at 17:37:18
My Computer specs:
Asus A8V-E SE motherboard
500 Watt Antec Powersupply
ATI HD x1950 Pro
AMD 3800+ X2 Dual Core Processor
(processor has some cooler, brand name is Gigabyte)

I don't do any overclocking or anything either, all default setup.

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December 17, 2009 at 22:51:13
How many harddrives? How many optical drives? Any other fans? If you only have one harddrive and one optical drive and one maybe two case fans 500 watts shouds be more than enough but I would not go below 400. It is better to have more than needed incase you choose to add something later.

Antec is good, Corsair is good, I have also seen thermaltake last a good while though I have not used one myself. Stay clear of the ones that offer 500watts for 29.95. Also you may want to look for a psu with a single (just one) 12 volt rail unless you have several different things being added then you'll need more wattage anyway. We have seen an increase in failures, at least in my opinion, of psu with multiple 12v rails. I am told this is due to the amperage being drawn is not balanced across the rails. Not sure if that is true but in the past few months I have replaced 14 multi rail psu's and only 2 single rail. One of them wasn't bad just needed more wattage, the other one was 9 years old.


I want to go like my grandfather did. Peacefully in his sleep. Not screaming at the top of my lungs like the passengers in his car.


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December 18, 2009 at 13:06:16
Just a couple of thoughts.

Both power supplies are bad.
One has power to the 4 pin connector but is failing on the 20/24 pin connector or a number of molex connectors.

The other is failing on the 4 pin connector.....

Or there might be a short on the board. A short will not allow the the green light to come on. The power supply needs to be 100% in order for that test to be run.

Having tons of parts and not afraid to let the smoke out....
a person can take the power supply with the non working 4 pin plug and add a 4pin to a molex connector.. (for testing)
Use a molex that is known to be working. (hd or cdrom plug)

Instructions can be googled.

Yes I can hear the groans of anguish from!

A power supply tester.....a cheapie can be had for under $10.00 on Ebay. Doesn't give wattage but will tell you if the psu is working at all.

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December 20, 2009 at 16:32:10
Yeah, I found a pretty cheap PSU tester on Ebay for around that price but if you think about it that $10 could go into another PSU!!!

BTW, 2 DVD drives(ones a burner, other is just DVD-Drive), one 200gb IDE HDD, and two case fans.

So should I try out another 500w PSU(insert brand name) or dwell more into this?

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December 20, 2009 at 17:15:05
I mentioned overheating. Obviously if your computer isn't running you can't check the system temps.

You can open the case and look for dirt/dust inside, including in the PSU.

I would go for another PSU at this point. I would suggest you buy something with a little room to grow. If you are in the USA then look at the links below.

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