Computer unresponsive to power switch

[Alpaca91]

I was usimg my computer which was on the ground when my brother lightly kicked my tower which made the screen say shutting down and turned off immediately. The computer was on for a few days and I figured it may have been overheated. After a few hours I tryed turning it on but it wouldnt do anything. Ive tested the power supply and it works fine. The gpu also works in a diff rig. So I've got it down to the mobo or cpu. When I conmected the green line to test the psu, I left the 8pin cpu power connected (by mistake) and the cpu fan started spinning, so I dont know if this means the cpu works or atleast this part of the mobo works. The problem seems to be around the 24pin input or the power on pins on the motherboard. Any suggestions to diagnose or test the problem part or any possible fixes

 

[charliewhiskey]

Unplugg the system and let it sit unpowered for 10 minutes. Start. if it does not start, make sure everything internally is tight. Reseat the Ram and check the MB connectors including the HDD. You might even try resetting the CMOS to force the MB to default settings.

 

[azaran]

First thing, When you say you tested the PSU, how do did you test it?

I'd recommend trying to take your case switch out of the equation.
Reseat the 24pin and 8pin connectors on to the motherboard. Then try and turn on the computer manually without the case switch. If you motherboard doesn't have a power button (high end boards tend to) you can simply use a screw driver to jumper the pins on your front header on the motherboard. Usually it'll be marked as "Power" or something to that effect, a flat head or phillips will work just fine. All you're trying to do is touch the two pins so it effectively turns it on the same way the case's switch will. If it fires up, great you know its the case that has a faulty switch. If it doesn't power up then chances are they're something off with your PSU. Testing it with a known good PSU will help determine if there's a problem else where in the computer.

 

[Alpaca91]

When I tested the psu, I connected the green line to a gnd, with a cable, the psu turdned on with some fans connected as a test. As far as reseting, how would I go about that?

 

[azaran]

Reseating, take the plug fully out and then fully place back in to the motherboard. Make sure its seated fully in the socket. You'd be surprised how often a bad PSU is really just a badly plugged in PSU.

 

[Alpaca91]

Oh, yes I have reseated the 24 pin, ive even tested the whole system with a different psu. what bugs me about the situation is with both psu when I hit the power button, nothing even flinches, no fan turn for even a split second. If it was a loose part or cable id imagine that the fans would at least spin for a split second before shutting down

 

[azaran]

Thats why I'd recommend turning it on manually instead of using the cases power button. If the case is shorting out, or if a spring isnt working right it can cause whats happening. Now granted it could also be a matter of dead hardware else, but its also an easy test to do before you start ripping out the motherboard.

 

[azaran]

For a quick and dirty video to see what I mean by turning it on with a screw driver, this guy has a youtube video. At about 45 seconds he's doing what I'm talking about.
https://www.youtube.com/watch?v=G4FOBL1c3pA

 

[Alpaca91]

Im not sure exactly what was the problem, but heres what I have so far, using the screwdriver method wasnt working, but I uninstalled the cpu cooler and put in a new one then tried again with the screw driver method and it worked, so it may have been a combination of broken power button amd loose cooler

 

[azaran]

Im not sure exactly what was the problem, but heres what I have so far, using the screwdriver method wasnt working, but I uninstalled the cpu cooler and put in a new one then tried again with the screw driver method and it worked, so it may have been a combination of broken power button amd loose cooler

Well great, sounds like you've gotten PSU, CPU, Mobo, etc out of the equation. Double check any connections to make sure their firm in there, plug your case switch in to the right spot and try it again. If it turns on, cool, then wiggle the case and see if it shuts it down again. If its moment that causes to shut down, you may have a wire shorting against the power button wiring. Track it through and see where it gets you.