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Sort of a followup to this question. The mobo's getting power, the lights are on. The GPU fan is spinning (it doesn't use auxiliary power, it's only connected to the mobo).

I'm not getting any video signal, and it's not the video card (nor monitor) that's faulty, so I'm suspecting mobo or CPU (possibly RAM?) and I'm trying to pinpoint which part is at fault.

Is the motherboard a candidate for being broken or is it not very likely if it's getting power and powering other components? The CPU fan is getting power as well.

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Power is not an indication of function, in my opinion.

The main test to check for a faulty motherboard is to remove all components from the system and try booting. Remove the video card, RAM and anything else that is hooked up. You can do this one at a time and see if you get any further in the boot process.

Also, is the computer booting? Do you hear the proper beeps and is your hard drive spinning up?

If it is simply a video problem and you know for sure that the system is booting properly, it is most likely your video card or possibly your video card slot on the motherboard. You should try the on board video (if possible) or another video card (if possible) to continue troubleshooting the issue.

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The case didn't come with system speakers, tried an old PCI video card (that's confirmed working as well) and that didn't go. No onboard video. I'm not sure what you mean by removing the video card and seeing if I get any further in the boot process. How can you tell without any video? Hard drive isn't necessary to get into the BIOS, so that's orthogonal to the issue. – Davy8 Dec 27 '10 at 15:54
Removing the video card was assuming there was on board video. If 2 confirmed working video cards have failed, then it is most likely a faulty motherboard that needs to be sent back/RMA'd. As a last ditch effort, you could try to remove the RAM and try booting, but it is unlikely to affect the video. Also, when I mentioned the hard drive spinning, you misunderstood me. If you hear the hard drive spinning, then you are most likely booting properly. That is what I was referring to, to confirm that it is strictly a video issue. Again, most likely a faulty motherboard if 2 good GPUs are failing. – th3dude Dec 27 '10 at 16:25
@th3dude so it's not likely (or not possible?) that bad CPU or bad RAM could be the culprit? I don't have any DDR3 or Socket 1156 mobo's around to test those with, so I can't eliminate those by swapping them out. – Davy8 Dec 27 '10 at 17:40
It's most likely the motherboard. Since you can't boot without CPU and/or RAM, it will be hard to be sure. However, you have yet to answer my question about your hard drive. Does it or does it not spin up and seem like it is booting your OS? The answer to this could be important. If it does seem like it is booting, it is strictly a video issue. If it is not (and the system is possibly attempting to post beep codes), then the problem may lie in the RAM or CPU. You can also test the RAM by removing all of the sticks and trying them one by one. – th3dude Dec 27 '10 at 19:04
Looks like it was RAM in the wrong slot, but +1 for a good answer. – Davy8 Dec 27 '10 at 22:12
up vote 1 down vote accepted

So it turns out I'm a retard and didn't know that it mattered which slots the RAM was in. I moved the RAM to slots 1 and 2 and it everything started working.

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It could be anything, any faulty piece of hardware can cause this condition including the power supply, you will need spare parts of everything to troubleshoot it, yes the motherboard itself could be bad.

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