Did I just fry my motherboard?

[yh125d]

So I was getting my brother's computer ready for him, messing with the fans and stuff to make it quieter, and I go to unplug one of the fans.

I unplug said fan, and lightly touch the bottom of the case with my hand (I felt a little discharge). I guess the case didn't like this, because I heard a small crackle, saw a glos on the side of my motherboard, and windows shut down (but fans were still spinning, including CPU fan, so I guess motherboard isn't entirely dead at this point). I yank the power cord as quickly as I could, pulled stuff out of the way and observed the damage

Wide angle
Looks like a mosfet on the edge of my board

Any thoughts? I haven't tried to power up the system or anything. It's still in its 3 year warranty, but I never registered online. Will I not be able to get a replacement

 

[Quiksilver]

Are you retarded working on a PC while it is still ON?

 

[yh125d]

Just unplugging fans and such. I've done it for years and no problems

I'm pretty sure the problem was caused by my static electricity discharging on the case, which is normal usually. I'm guessing that the mobo isn't properly grounded

 

[Qbah]

My old ASUS mobo lost a cap near the PCIE slots from the general temp of the system inside (Pentium D, a X1950XTX and 2 Maxtor drives - that's hot, trust me ). That was a few years back and the machine is still going strong without me doing anything about the MIA component. But that was a (somewhat big, but still) capacitor. Be a man and just start the machine and see what happens. I would do it (again ) cause I don't think anything major can happen.

 

[yh125d]

Argh, even if I do get it running, I won't feel confident about it. It will be going to my brother whos not computer savvy, so if anything does go wrong he's not going to be able to troubleshoot it



I might just switch motherboards and give him my P5Q for now

 

[TLW]

back to where you bought it with a note saying dead on arrival...

not ethical but financially the best way of going about it..

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[yh125d]

Originally posted by: TLW
back to where you bought it with a note saying dead on arrival...

not ethical but financially the best way of going about it..

Please do not promote fraud, it is violation of the forum guidelines located here Note in rule #4, what the Administrator states concerning the violation of U.S. laws-

No posting of other's copyrighted material. Discussions of copyright are becoming increasingly important, but we will not allow the Forums to be used to violate any US law.

Repeated violations of the guidelines will result in your posting privileges being suspended or revoked- Anandtech Motherboards Moderator-DAPUNISHER

Excuse me? I bought it two years ago with a three year warranty, but I never registered it (not sure if/how much that matters) so I might still be able to get it replaced (legally, I have no intention of defrauding Asus). If its burnt and I can't get a replacement, I'd just assume get a $50 mobo than risk trying to pawn it off on Asus

 

[DAPUNISHER]

Originally posted by: yh125d

Excuse me? I bought it two years ago with a three year warranty, but I never registered it (not sure if/how much that matters) so I might still be able to get it replaced (legally, I have no intention of defrauding Asus). If its burnt and I can't get a replacement, I'd just assume get a $50 mobo than risk trying to pawn it off on Asus

I wasn't implying that you would, which is why my response was to the member that suggested lying about it being DOA, and not yourself.

In my experience, registering makes little difference with most boards warranties. Also, if you are polite, and explain exactly what happened, sometimes support will let you RMA, YMMV.

 

[yh125d]

Originally posted by: DAPUNISHER

Originally posted by: yh125d

Excuse me? I bought it two years ago with a three year warranty, but I never registered it (not sure if/how much that matters) so I might still be able to get it replaced (legally, I have no intention of defrauding Asus). If its burnt and I can't get a replacement, I'd just assume get a $50 mobo than risk trying to pawn it off on Asus

I wasn't implying that you would, which is why my response was to the member that suggested lying about it being DOA, and not yourself.

In my experience, registering makes little difference with most boards warranties. Also, if you are polite, and explain exactly what happened, sometimes support will let you RMA, YMMV.

Ah, now I see. I didn't quite understand your edit first time around

Thanks for the info about registering. I had hear that some companies only honor warranties if registered within 30 days or some such, but I'll shoot them and e-mail and see what I can work out

 

[TLW]

Originally posted by: some guy

Please do not promote fraud, it is violation of the forum guidelines located here Note in rule #4, what the Administrator states concerning the violation of U.S. laws-

No posting of other's copyrighted material. Discussions of copyright are becoming increasingly important, but we will not allow the Forums to be used to violate any US law.

Repeated violations of the guidelines will result in your posting privileges being suspended or revoked- Anandtech Motherboards Moderator-DAPUNISHER

wow, jumping to conclusions there - if you read what i said i never promoted such an action, i actually said it wasn't ethical, make of that what you will...

 

[Ratman6161]

Thanks for the info about registering. I had hear that some companies only honor warranties if registered within 30 days or some such, but I'll shoot them and e-mail and see what I can work out

Doesn't really matter. If you fried it with a static discharge then that is not covered under warrantee - registered or not. The board was not defective - you broke it by handling it improperly.

 

[NoStateofMind]

Originally posted by: Quiksilver
Are you retarded working on a PC while it is still ON?

Originally posted by: yh125d
Just unplugging fans and such. I've done it for years and no problems

I'm pretty sure the problem was caused by my static electricity discharging on the case, which is normal usually. I'm guessing that the mobo isn't properly grounded

Maybe next time you will NOT work on it while its on. It's just common sense. Not trying to be rude, but if you play with fire long enough you will get burned (or your motherboard )

 

[yh125d]

It shouldn't really matter much that it was on. If the discharge was gonna burn something, it was gonna burn something. Being off wouldnt have stopped that

 

[lowrider69]

Originally posted by: yh125d
Just unplugging fans and such. I've done it for years and no problems

Except for now.

 

[skyskeek]

you should always ground yourself when working on any electronics,not just unplug it, all this does is kepts you from getting jolted it doesn't kept you from jolting the system this is true on any system whether it be a game system, computeror any thing electronic.you can get a grounding strap that goes around your rist from an electronic supply dist.

 

[William Gaatjes]

That component is gone. I am sorry for you but it's over. If you can manage to find out what kind of component it is by looking at the numbers on a still working motherboard of the same model and are able to replace it you might get it working again. But it could be you damaged a whole lot more... My advice don't do that anymore. It all works fine for 9 times but the 10th time something happens. My brother has the same problem and never learns after i repeately mentioned the dangers of electrostatic discharges (ESD) or short circuits.

Every once in a while computer parts die on him for no apparent reason.


Grounding yourself is important but make sure the case of the pc is grounded too and connected to the GND of the motherboard. This is usually the case by use of screws.

At least always touch the ground parts of your pc or components before touching anything else like pins on a connector or electronic components. This way you will have the same electric potential as the ground plane from the pc or just seperate add in cards. You will save yourself this way a whole lot of trouble. If you really want to be on the save side buy an esd wriststrap with a cord and a crocodilebeak to ground yourself on a save way and keep the same electric potentional. Just connect the crocodile beak to the ground of the pc like the blank part of the case or some screw. Or to the GND back plate of the seperate add in card. The back plate is the metal L shaped which you can screw or click on to the case.

 

[yh125d]

Anyone know where I could buy a new mosfet? its an AP3310GH

 

[William Gaatjes]

Well here is the datasheet.
.

http://download.cizgi.com.tr/akademi/1205/ap3310gj.pdf

I think the best chance is to find another defect board where this component is good.

I looked at the datasheet and it seems like a component with very common characteristics but i do not know where you can buy a similair component. Farnell does not seem to have it.


I may be wrong but when i look at the picture it seems that this mosfet is connected to the fan connector. Probably used as to control the fan voltage and therefore fan speed. Do you know if that motherboard has that capability ? If that is the case you might get away with connecting the source and the drain (see datasheet) you will have no more fancontrol but at least the fan will spin. It is a big if tho, if you are not at home in electronics just ask someone who does if that person is willing to do some measuring with a multimeter with circuit testing functionality on the board without any power applied to it = completely shutoff. Even better is the board just seperated. The drain should be connected to the positive wire (+) of the fan. If that is the case you might be in luck. The source should be connected to the +12V.

 

[Edgeoc]

That did not happen from static. You plugged something back when it was hot err running/plugged in and shorted out what's most likely the fan bus pwr regulation mosfet.

Good stuff...

 

[Mark R]

While you may be able to replace the component, you don't know what else has been damaged.

That MOSFET is part of a voltage regulator for part of the motherboard - probably for the south bridge chip. It's certainly nothing to do with fans. What likely happened was that a static discharge caused the regulator control chip to suffer latch-up, causing both MOSFETs in the regulator to turn on simultaneously (the role of the controller is to turn each on alternately at a precisely controlled ratio). The result was a massive current surge through both MOSFETs, and the weaker of the pair (the high-side driver p-channel MOSFET) burned first.

The problem is that the static discharge may have damaged the controller - in which case, there's no point replacing the MOSFET, because the new one will just burn up as well. The other problem is that the regulator malfunction may have allowed excessive voltage to build up on the output - potentially toasting all the circuits supplied by the regulator (e.g. the south bridge), which won't be fixable.

Personally, for a budget motherboard like the P5B, I wouldn't waste time even thinking about repairing it. Just replace it, and hope that all your RAM and peripherals still work.

 

[yh125d]

Yeah I've tested everything else, and it's all undamaged. I had an extra cpu and some ram laying around so I figured I'd give it a go. I hooked it up and powered it on. It powers on and the fans spin up, but only for a moment, 1-2 seconds maybe, then it shuts off and repeats until I pull the paper clip out

 

[yh125d]

And I'm definitely handy with electronics/soldering if I decide to try and replace it. I think it'd be a fun little project. Back in high school I built stuff like my own phone, a robot that followed a line of tape, marble sorters (by color), etc. in my engineering class

 

[William Gaatjes]

Originally posted by: Mark R
While you may be able to replace the component, you don't know what else has been damaged.

That MOSFET is part of a voltage regulator for part of the motherboard - probably for the south bridge chip. It's certainly nothing to do with fans. What likely happened was that a static discharge caused the regulator control chip to suffer latch-up, causing both MOSFETs in the regulator to turn on simultaneously (the role of the controller is to turn each on alternately at a precisely controlled ratio). The result was a massive current surge through both MOSFETs, and the weaker of the pair (the high-side driver p-channel MOSFET) burned first.

The problem is that the static discharge may have damaged the controller - in which case, there's no point replacing the MOSFET, because the new one will just burn up as well. The other problem is that the regulator malfunction may have allowed excessive voltage to build up on the output - potentially toasting all the circuits supplied by the regulator (e.g. the south bridge), which won't be fixable.

Personally, for a budget motherboard like the P5B, I wouldn't waste time even thinking about repairing it. Just replace it, and hope that all your RAM and peripherals still work.

That was my fear from the start too. But i could not have explained it better then you did even if i would have tried.

 

[oldfartjc]

Originally posted by: Edgeoc
That did not happen from static. You plugged something back when it was hot err running/plugged in and shorted out what's most likely the fan bus pwr regulation mosfet.

Good stuff...

+1 Static discharge to the case would not have caused your problem, no way.

 

[Rinaun]

Agreed.,this doesn't look like static discharge. I'd believe the charge started the issue, but if it had just been that, I don't think the top of the mofset would be melted. I think this has more to do with him running the PC on while working on it.