# I need to repair a blown fan header on my motherboard!



## Q9650

I was checking the voltages on my motherboard`s fan header with a digital multimeter and accidentaly i shorted the pins and caused a spark enough to blow it! I need to know if the transistor supplying the +12volts to the fan is still fine or what SMD compnent has been damaged? The traces on the board are still fine so if someone can tell me how to repair it i will be very grateful! the blown fan header is 4pin PWM type.

here is a screenshot of the blown fan header sys_fan2.

the header still reads the rpm speed but someone on other forums told me the mosfet transistor or the cap maybe be damaged and need to be replaced










Note: this is not a screenshot of my actual board (board is a gigabyte GA-EP45T-UD3P) i got it from google


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## KillServ

If you put a picture of your mobo it may help people in helping you as it may or may not show the damage.


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## Q9650

my board is in the case right now so i cannot take photos of it


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## YanYan001

If its still under warranty then I would suggest that you call in and tell them it just died on you:sozo:....heheheh:rolleyess

then customer service:headsetsm be like








then he be like








finally he be like


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## Q9650

OK !!! i did it!! i replaced the mosfet transistor and now the fan header is back ..it`s alive it`s alive!!!


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## kill

Nice gratz on the repair


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## frozenreads

Dang it! I did exactly the same thing to my Rampage III Formula! Was having issues getting the CHA FAN headers to work correctly and decided stupidly to multimeter test them all and shorted not one but two of my OPT Fan headers! Can you give me some further details on how to find and replace the component. I am fairly competent with a soldering iron! I dont really use the OPT Fan headers so not sure if I should bother or not to attempt repair.


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## Q9650

Quote:


> Originally Posted by *frozenreads*
> 
> Dang it! I did exactly the same thing to my Rampage III Formula! Was having issues getting the CHA FAN headers to work correctly and decided stupidly to multimeter test them all and shorted not one but two of my OPT Fan headers! Can you give me some further details on how to find and replace the component. I am fairly competent with a soldering iron! I dont really use the OPT Fan headers so not sure if I should bother or not to attempt repair.


first take a note of the damaged MOSFET transistor part number and try to desolder one from another asus mobo. first heat up the transistor with a special heat blower for smd devices to melt the transistor legs, be careful as underneath the transistor it is spot glued and you need also to melt this glue so it can be detached from the mobo.

In my experience mosfet transistors are very sensitive to short circuits and i think you have blown it up like i did by shorting the fan header pins with the probes.

good luck in restoring back you fan header!


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## frozenreads

Sorry for the delay in response, I had attempted to send the board back for repair to ASUS and although they did not send anything to me to say they had refused to repair, the board came back unchanged. I just want to double check the faulty component with you. Basically after shorting the CPU headers any fans connected still operate but they run at their slowest speed (normally with these headers and power control switched off they operated at full speed). In this particular case my second CPU fan that I have connected to OPT_FAN1 normally runs at its fastest speed of 1900rpm, now it just runs at 900rpm. So there is obviously power getting to the CPU header but the fan will only operate at a slow speed. Any thoughts to what I have blown and need to replace? Really appreciate your feedback by the way.


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## Q9650

@frozenreads what is the type of fan you are using with the blown header? pwm 4wire or standard 3pin? all i can see here is that you may need to replace the blown mosfet with a same type...then your fan will spin at full speed your mosfet is shorted and now it is supplying a lower voltage then 12v so it spins slower. if you replace the mosfet transistor with a new one and the fan does not spin full speed you may try to solder a small wire from a 12v print on the board and link it to the +12v on the header it works always like this. goodluck!


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## frozenreads

I have tried both 3pin and 4pin fans. The Rampage III formula comes with 3 x OPT_FAN headers, they are 4 pin but I believe they are not PWM. I believe I have damaged OPT_FAN headers 1&2 (dont ask - long story, I got over enthusiastic with my multimeter. This board can control fan speed to these headers within the BIOS but with this switched off normally the headers run the fans at full speed. Now after my heavy handiness they do not, they just run at a very slow speed. The repair job is probably a little beyond my soldering capabilities, I am not really sure how to go about getting these fixed. There really is nothing wrong with the rest of the board so there is no point in replacing it, for a couple of damaged fan headers. ASUS obviously will not repair it under warranty so I am not sure how to proceed. lol, do you fancy having a go at repairing my board? Willing to pay for the repair!


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## joder

Quote:


> Originally Posted by *Q9650*
> 
> OK !!! i did it!! i replaced the mosfet transistor and now the fan header is back ..it`s alive it`s alive!!!


I hate digging up a very old thread, however, it is the one most pertinent to the issue I created.

I too was testing some voltages and shorted the +12V/Speed Control pin with the ground pin.

The system immediately shutdown (I guess for safety purposes).

The Sys Fan1 header still works, however, it is at full speed now. This header can be controlled by voltage or PWM IIRC.

The pins are GND, +12V/Speed Control, Sense (RPMs), VCC

I would like to make it controllable by voltage again, however, I am not sure that this will be an easy task. I have looked at the board around the header and cannot see anything that has been fried. Any clue on what could be blown that won't allow it to voltage regulate now?


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## maroslav

Hi guys,
I have a simlar problem with my motherboard. It is asus p6x58d-e (socket 1366). Using a multimeter I made a short circuit on the fan header. Fan isn't spinning (0 V) and q-fan profiles doesn't work on all fan headers (voltage regulation). Any ideas?


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## FrodeL70

I also hav e a similar problem with my ASUS Rampage II Extreme LGA1366 MOBO. I can't figure out what part I need and where to get it. Anyone care to help?



The voltage regulator (mosfet) have markings on it: NIKOS PA102FDG but then it have aditional markings : WBC8L0613 (?)



Image is of an nearby and similar transistor as the one that blew has a hole in it.

Is it possible to replace this regulator?


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