My computer is dead...need help...

[Tar2010]

Hi guys


I was hoping for some relaxing days in front of my PC this easter holiday but my pc is now dead.

Last night I was putting the SLI bridge back on my videocards after doing some game testing. The pc was turned off, power cable was still attached and PSU was not turned off, but everything seem to go well. But for some reason the pc would not start up again.

This is the situation:
When I turn on the power switch on the PSU I just get a very short flash of light from "standby" light on my motherboard and from my CPU watercooler before it go completely dead. The power switch doesn’t work at all and there don't seem to be any power anywhere. I get no signal of any life no matter what I do. To get the quick flash back again I have to leave the pc alone for some time and when I push the power switch on the PSU I get this small flash of light before it is dead again.

What I have tested so far:
PSU: I took out the PSU and quickly attached it to my very old backup computer. I only plugged in the 24 pin plug for the motherboard and I was able to start up that computer, so the PSU seem ok at least.

I have unplugged all things attached to the motherboard and the PSU like USB, HDD’s etc, and tried to start up with as little as possible connected. Nothing seems to work. I have tried with only attaching the 24 pin connector, then the 24 pin connector and the 8 pin for CPU, and so on.

My questions:
1. What hardware is minimally required to get the motherboard “standby” light to turn and to boot? I was thinking just CPU but I’m not sure, do I need a USB unit, Ram and a monitor connected also?
2. How should I approach this to find out what is wrong? I think something is either wrong with the motherboard or CPU but I don’t know for sure. Should I reset the motherboard, take out the CPU.
3. Is there a way to separate a defect CPU from a defect motherboard?

Other info:
I’m overclocking and using custom cooling on CPU and videocards. I have done this the last 10 years and I never push to extremes and keep within safe voltages.
I had an accident with my pc 2 weeks ago where one of my GTX 980 that I had custom cooling on got burned due to overheating. The watercooling kit gave very bad cooling to the rest of the components and some very small chips got burned.

My current hardware:
Motherboard: Gigabyte GA-Z97X Gaming G1
CPU: 4790K @ 4.8 GHZ @ 1.32v
GPU: GTX 980 SLI @ 1432 mhz @ 1.21v
PSU: Corasir AX1200

Any help would be highly appreciated.
Cheers

 

[master_shake_]

try motherboard cpu one stick of memory no gpus or hdds or ssd attached.

see if you can get it to post.

 

[master_shake_]

also check the voltage on the purple wire should be 5vdc

 

[Burpo]

Remove both video cards..

Does it post?

 

[Tar2010]

Thanks for quick replies guys, really appricate it

try motherboard cpu one stick of memory no gpus or hdds or ssd attached.

see if you can get it to post.

I have tried this, no luck so far. Also tried with cpu cooler unplgged or plugged. Did also try with only 24 pin connector and the 8 pin connector to the motherboard.

also check the voltage on the purple wire should be 5vdc

The AX1200 from corsair have only black wires

Remove both video cards..

Does it post?

Have done that, no success sadly..

 

[master_shake_]

 

[master_shake_]

psu switch on

 

[Tar2010]

Hmmm Im not sure how i can measure this. I thought the PSU need to be connected before getting active, or can I just measure the voltage directly into the 24 pin plugg without having it connected to the computer?

Btw, is this to test if the PSU is working? I allready plugged the 24 pin plugg into my old backup computer and it started up. So think the 24 pin plugg is ok, but maybe this is a better test.

 

[master_shake_]

you can measure the 5v stand by with the 24 pin disconnected and psu on.

that is what lights up the stand by light.

 

[Tar2010]

When I start testing the voltage of my PSU maybe someone could help me with the questions I posted in my first post:
1. What hardware is minimally required to get the motherboard “standby” light to turn and to boot?
2. How should I approach this to find out what is wrong?
3. Is there a way to separate a defect CPU from a defect motherboard?

thanks for any help

 

[denis280]

I had an accident with my pc 2 weeks ago where one of my GTX 980 that I had custom cooling on got burned due to overheating. The watercooling kit gave very bad cooling to the rest of the components and some very small chips got burned.

This is what i don't like.I don't think the cpu is fried,but pretty sure the mobo is.

 

[ninaholic37]

edit: Disregard

 

[Ketchup]

If nothing on your board is getting power, it would be the ps or the board IMO. Since you have ruled out the ps, I think we can know where the problem is. This is not to say there can't be a short somewhere, which I would recommend checking, possibly by getting the board outside the case, but I think your problem is related to the board in some way.

 

[ninaholic37]

edit: Disregard

 

[Tar2010]

Hi again and thanks for all help guys

I did not found my ohm meter so I did not measure the voltage, but I did one thing that have fixed my problem, at least so far.

I removed the battery on the motherboard and cleared the CMOS. Then my PC started, and to my surprise all settings in BIOS was still there. So right now everything seem to be ok.

What do you guys think can have caused this?
I wonder if it is possible that the reason that it happened could be because I still had the power cable attached when I put the sli bridge back. Maybe the motherboard detected some kind of "short circuit" or other failure and put the board in some kind of protective mode.
Or can it be a warning that some hardware is about to die, or that something else is wrong that can cause this to happen again? What you think guys?

 

[denis280]

I had an accident with my pc 2 weeks ago where one of my GTX 980 that I had custom cooling on got burned due to overheating

This. and your lucky my friend Glad it turn out fine

 

[Tar2010]

This. and your lucky my friend Glad it turn out fine

ok, thanks

Im just afraid that this was a indication that my system is getting unstable and that something is about is about to fail, like my PSU or something.