Computer wont boot when 12v 4pin is plugged.

Status
Not open for further replies.

jervhen

Distinguished
Apr 7, 2011
5
0
18,510
Yesterday I was playing my computer, then suddenly shuts down. I tried to turn it on again but i only hear a fading beep. The beep was not the usual beep u hear from an hardware error such as RAM. A sweechh sound like to be exact. I thought it was the PSU, so i changed my PSU but nothings differ :fou: . After that I remove all components inside the casing and assemble it outside it. I checked my RAM, Processor and Graphics card and all are working fine to my cousins MoBo.

Suddenly, I noticed that when I remove(unplug) the power going through the 12v 4 pin on the board, everything works perfectly. Unfortunately the monitor won't show anything. I believe that this is a secondary power for the monitor (12v 4pin).

I tried searching :pfff: through the internet but nothings coming up for a better solution. Tried everything from threads to threads but still stock here.

-----Specs of my tower----
CPU: q9400
Video Card: Palit 9600
Mobo: intel DG41RQ
PSU: ATX- 600w or p4 - 500w
Ram: DDR2-800 PC6400 2G/128X8

Please help :ange: ! I appreciate all recommendation that will help! :)
 
Solution

It's quite possible that a VRM (Voltage Regulator Module) on the motherboard has become defective.

banthracis

Distinguished
Err the 12v 4pin-8pins are actually for CPU power, assuming you're referring to below 4pin socket

jtkves.jpg


PC shouldn't boot without it.

If it does still, then you're got a seriously messed up mobo.

Either way, if you've ruled out PSU, RAM, PSU, and GPU then only thing left is a bad mobo.
 
It is not the secondary power for the monitor.

Intel_DG41_RQ_Power_Connections.jpg


In the Intel DG41RQ image above the 2 x 2 pin connector is the processor core power connector. It provides power directly to the processor voltage regulator and must always be used. If it's not connected the board will fail to boot as the CPU is receiving no power.

All of the remaining components on the mother board get their power from the 2 x 12 or 2 x 10 power connector which would explain why fans spin up and some LEDs light up.
 

jervhen

Distinguished
Apr 7, 2011
5
0
18,510



yap. thats it. Ow i see! I was hoping for a fix, but surely its an end of it. thank you then. Appreciate it. :)
 

jervhen

Distinguished
Apr 7, 2011
5
0
18,510


I didn't know that. That's a great info from u sir. Very Knowledgeable and informative. ;)

Then there fore concluded that this is a dead Mobo then right?

Thnx you sir.
 

It's quite possible that a VRM (Voltage Regulator Module) on the motherboard has become defective.
 
Solution
Status
Not open for further replies.