Rebuild Help

niggyg · 31 Oct 2010 at 09:34

I just installed a Noctua NH-U12P cooler. I'm testing the system outside of the case with just the MOBO+RAM+Graphics+CPU. When I power on the fans power up for ~1 second and then power off. Strangley this cycle continues untill I turn the power off.

I've removed the cooler and tried the old one again and I still get this behaviour. When I removed the CPU entirly the fans power up without being cut off. Though I'm still getting no video signal in this instance, is that normal?

It seems like I'm getting a short but I can't think how as I'm doing this outside of my case and with minimal hardware attatched.

PSU: OCZ 600w
MOBO: P6T SE
CPU: i7 920 C0

Any suggestions?

RJC · 31 Oct 2010 at 12:15

Were you previously overclocked, try reseting the CMOS.

niggyg · 31 Oct 2010 at 12:36

RJC said:
Were you previously overclocked, try reseting the CMOS.

Nope, stock settings. The only thing I can think is I must have somehow damaged the MOBO.

acharris · 31 Oct 2010 at 15:39

Hi, you did plug the 12v lead in for the cpu did you and connected up the CPU fan to the CPU connector on the mobo?? Also if you remove the CPU completely then yes you will get no signal as the CPU is the brain and the mobo dont detect the cpu and hence the post. Also did you apply thermal paste and also did you remove all the old thermal paste before fitting the new cooler.

Check your power connectors again for the 12v and also what are you running the board on?? cardboard, table, maybe you dislodged a ram stick, is there enough room over the edge so the the card plugs in all the way or is the metal back plate of the GPU card hitting the table. Also did you use a screwdriver to short the power on pins and did u accidentally touch the screw driver somewhere on the mobo. Worth checking these for peace of mind.

niggyg · 31 Oct 2010 at 19:08

acharris said:
Hi, you did plug the 12v lead in for the cpu did you and connected up the CPU fan to the CPU connector on the mobo?? Also if you remove the CPU completely then yes you will get no signal as the CPU is the brain and the mobo dont detect the cpu and hence the post. Also did you apply thermal paste and also did you remove all the old thermal paste before fitting the new cooler.

Check your power connectors again for the 12v and also what are you running the board on?? cardboard, table, maybe you dislodged a ram stick, is there enough room over the edge so the the card plugs in all the way or is the metal back plate of the GPU card hitting the table. Also did you use a screwdriver to short the power on pins and did u accidentally touch the screw driver somewhere on the mobo. Worth checking these for peace of mind.

Thanks for the input, 12v power is connected to the MOBO as is the main power. Thermal paste was removed and re-aplied correctly. I checked the RAM and graphics cars were firmly in. I was doing the setup on carpet. Is this likley to be the problem? If so I'll have another bash once I've got the nipper in bed.

B1ng · 31 Oct 2010 at 19:26

On carpet!?

There's a chance you may have frazzled something via static damage; try it on a non-static surfce such as a wooden table.

niggyg · 31 Oct 2010 at 19:39

B1ng said:
On carpet!?

There's a chance you may have frazzled something via static damage; try it on a non-static surfce such as a wooden table.

Hmmm, you live and learn, I'll give it a go on cardboard now. Any chance I'd get away with RMA-ing this or would it be picked up?

niggyg · 31 Oct 2010 at 20:53

Just re-tried on cardboard (and with clearence for the graphics card hinge). Same result,

Is this definatly the MOBO fried?

acharris · 31 Oct 2010 at 23:34

Mmm it definately sounds like that the mobo could be fried, or it could be the CPU as you said with the CPU in it dont stay on, but with the CPU out it stays on and the fans spins the CPU could be fried. You havent got any thermal paste on the CPU socket have you and it is causing a short between the CPU and socket where the paste is???

Worth a check or otherwise it is just a situation of live and learn

niggyg · 1 Nov 2010 at 07:40

I cant see any, but it's AS5 which is nonconductive?? I only applied a small amount. The MOBO is still in warrenty, I found the recipt from OCUK, though it's to another user. Is there any way I can tell if it's the MOBO or CPU that's causing this?

danza · 1 Nov 2010 at 07:51

Modular PSU? Check the cables/swap them around.
Is the video card connected with its 6 pin plug?

I've had this problem several times, and it's always been down to dodgy wiring on my part. The three occasions where I've had a dead mobo I've had nothing out of the PC, but I'd imagine you could get a twitch from one depending on what was dead. I don't know if there's an easy way to tell if it's the CPU or mobo without having a spare one of either to play with.

I'd try it in the case as well. I'm not sure how motherboards react without being earthed to the case, so maybe worth a try.

niggyg · 1 Nov 2010 at 09:18

danza said:
Modular PSU? Check the cables/swap them around.
Is the video card connected with its 6 pin plug?

I've had this problem several times, and it's always been down to dodgy wiring on my part. The three occasions where I've had a dead mobo I've had nothing out of the PC, but I'd imagine you could get a twitch from one depending on what was dead. I don't know if there's an easy way to tell if it's the CPU or mobo without having a spare one of either to play with.

I'd try it in the case as well. I'm not sure how motherboards react without being earthed to the case, so maybe worth a try.

Is the video card connected with its 6 pin plug? - Yep.

The only cable that is changeable is the one to the graphics card and I know that is fine. Trying back in the case won't help here, I've had it setup outside of the case multiple times before without problem.

Does anyone know how OCUK handle warranty when your not the purchaser? I have the invoice.

acharris · 1 Nov 2010 at 18:09

danza said:
Modular PSU? Check the cables/swap them around.
Is the video card connected with its 6 pin plug?

I've had this problem several times, and it's always been down to dodgy wiring on my part. The three occasions where I've had a dead mobo I've had nothing out of the PC, but I'd imagine you could get a twitch from one depending on what was dead. I don't know if there's an easy way to tell if it's the CPU or mobo without having a spare one of either to play with.

I'd try it in the case as well. I'm not sure how motherboards react without being earthed to the case, so maybe worth a try.

As long as a mobo is run on something non-conductive like carboard or wooden surface everything is ok. A motherboard aint earthed on a case as the brass risers are used to make sure that the board dont short out on the metal chassis of the case.