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CPU or Motherboard DOA?

  • Gigabyte
  • Motherboards
Last response: in Motherboards
July 3, 2009 11:35:14 PM

One of them has to be and this is why I rule out everything else:

First I plugged everything in, got all the hardware in place, put all the PSU's chords in order, tried turning it on: nothing.

I thought the PSU was DOA but learned otherwise when I did the paperclip trick and the fan to the PSU started spinning, plugged in other hardware and saw that it gave it power. (CD drive, multiple fans, HDD), but when I take the paperclip out, and plug it into the mobo: nothing. Nothing at all.
That being said, I have taken the mobo out and placed it on a non conducting surface to see if it was the cases screws that could be doing the damage.
Still nothing, no PSU fan spin OR CPU fan spin. I read somewhere the CPU could cause this. Sounds to me like the mobo is DoA, but this is my first build. I've done a lot of research and was hoping nothing like this would happen but I don't know what I could have done. Please help with some closure or other ideas. Thanks.

More about : cpu motherboard doa

a c 242 V Motherboard
July 3, 2009 11:39:01 PM

It would have really been helpful to have a list of components. You didn't forget to connect the CPU ATX power cable (4 or 8-pin)?
July 3, 2009 11:43:25 PM

I connected all of the connectors necessary, including the 4 pin ATX

Forgot my spec's, they are:

Gigabyte GA-MA790XT-UD4P
AMD Phenom II x3 720 BE
8GB Mushkin DDR3 1333
Corsair 650XT 650 Watt
Sapphire ATI Radeon 4850 PCI Express 2.0
Sony DVD Drive
Western Digital 500 GB SATA
Cooler Master Centurion 5 Case
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a c 242 V Motherboard
July 3, 2009 11:46:13 PM

What's installed? CPU, video card and one memory module?
July 3, 2009 11:47:13 PM

I've mixed it around, but yea the original few tests were one stick of RAM, the CPU + HSF, the video card
July 3, 2009 11:49:16 PM

When I even only plug in the motherboard (both ATX connections) the PSU fan does not start, nor can I hear the little high pitch noise you can slightly hear when you turn the PSU's on. But the PSU fan turns on with the paperclip trick
July 4, 2009 12:52:28 AM

UPDATE: Have plugged in the PSU into another system I know works and I am posting from it now, so that basically rules out the PSU.

So I'm back to where I thought I was, how will I know it's the CPU or if it's the mobo?
Thanks for any help.
a c 177 V Motherboard
July 4, 2009 12:58:23 AM

Have you tested your power switch for continuity when depressed? Tried it by shorting the power switch header pins, with say, a screwdriver blade?
July 4, 2009 1:00:28 AM

I have not, how would I go about that?
a c 242 V Motherboard
July 4, 2009 1:09:01 AM

Briefly short out the 2 pins where the power switch normally connects to the motherboard.
July 4, 2009 1:30:34 AM

What Bios' do you have for board. You need the F4G Bios. There been reports that the original Bios were bad and you need to Flash to lastest Bios'.

a c 177 V Motherboard
July 4, 2009 3:59:37 PM

To test the board itself - the connector you're looking for is here:

and here's a little more realistic blowup of the actual header:

You are interested in the pins marked "Power Switch"... With everything else plugged in as usual, remove the little plug (we'll test it later) and do thusly:

with a fairly small flat-bladed screwdriver. You just need to short the pins for a moment. If the thing powers up, the switch itself is suspect...
For the next test, the easiest way is to use a multimeter, otherwise known as a VOM (Volt-OhmMeter); if you don't know anyone you can borrow one from, you can pick one up for under $20, including shipping (every human being should own one):
Try to avoid the otherwise obvious trip to RadioShack - they'll certainly have an assortment, but you'll pay approximately twice what they're worth!
Here is a video tutorial on the basics of using one...
What you'll need to do is stick a couple paper clips into the end of the switch's plug, put a meter probe on each of them, and have someone depress the button while you test either continuity (if the meter has that setting - most do), which will cause the meter to beep - beep:o K, no beep:switch bad; or test resistance zero ohms:o K, anything else:switch bad...

Good luck! Any questions, feel free...

July 15, 2010 1:12:22 AM

bdonedge said:
When I even only plug in the motherboard (both ATX connections) the PSU fan does not start, nor can I hear the little high pitch noise you can slightly hear when you turn the PSU's on. But the PSU fan turns on with the paperclip trick

Did you ever solved the problem? I am having an identical problem now. Except mobo is ASRock 890FX DELUXE3 AM3 and PSU is Corsair TX650

Passed the paper clip test, but with mobo out of case and only power fan and cpu fans connected, still nothing.

Thanks for the feedback

July 15, 2010 2:25:26 AM

Yeah, it turns out it was a bad power on button from my case
July 15, 2010 5:55:51 AM

woops ... meant to post on another thread.

== edit ==