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Computer lights up but does not show anything on screen.

Last response: in Systems
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December 17, 2011 11:28:15 AM

Hey guys,

I've had this problem with my pc for about a month, and its driving me mad. I press the power on button, the case lights up and fans start whirling, but nothing gets through to show on screen. I had one instance where I pressed the power on button, the computer began to start, powered off, and then started up again, all with nothing on screen. Its a homebuilt machine with:

Intel Core 2 Quad Q8400 2.66GHz Socket 775 1333FSB 4MB L2 Cache

P5B Asus Motherboard

2 sets of paired ddr2

Nvidia 8800 GTS graphics card

Creative Sound card

WD Cavier hard drives

600w Antec PSU

I have done the following:

Barebones start up, with just the GPU, CPU, MB and PSU. This resulted in no beeps at all.

Reseated everything save the CPU, MB and PSU. Dusted various parts with canned air.

Removed all the Ram. No Beeps.

Placed a single stick of ram in the closest slot. No beeps.

My thoughts:

I don't think the Pc is getting to POST, as I should be getting beeps from various things (though I can't spot the onboard 'beep maker' so not 100% that this mb has that feature.). This implies to me that the issue is with a dead motherboard or with a faulty power supply. Is my reasoning sound? Sadly, I have no replacement parts with me to swap out and test, so I have no way on knowing which it is. Thankfully, I was planning on making a new pc soon anyway, so I am happy to buy replacements for both. This brings me to my second question.

Could you guys suggest a replacement motherboard? I plan to upgrade to sli, and I can't find a single decent sli capable 775 socket motherboard for sale by a uk stockist. Have they gone out of fashion or something? :p  Either way, if you could recomend one I'd really appreciate it. I imagine that I simply need to upgrade my PSU to a model with around 800w, for the increased power needs of the sli setup.

Thanks for your thoughts!



December 17, 2011 3:35:25 PM

Oh, and I should add, I did manage to swap the screen and can confirm that it is not a monitor problem.
December 17, 2011 3:54:39 PM

Hmm...
This happened to me when I was building my latest PC.
The culprit was a bad Reset button on the case.
In case you were using the case buttons to start up the PC (even when barebone), try this:
Test your build with only the power button pins connected (or even without them, shorting with a flat-head screwdriver the power button pins on your mobo) and check if it POSTs.
If it does, start connecting the remaining connectors one by one, booting and checking for POST, until you find the faulty one.

Here's one indicator that sold the problem for me. Check if you can turn the PC off by holding the power button. When I had the problem, holding it wouldn't do anything,, I had to power down the PC using the PSU switch. Sometimes, shorting case circuits cause this kind of behavior.

You should try your GPU in another PC also, in case that's the problem.
!