ASUS motherboard blown TVS diode?

[felon637]

Hey guy's, new to this site and need some help.

I have a K60IJ laptop with a K50IJ motherboard in it that I bought a few years back. My daughter was using the computer one day and yelled "Dad there is smoke coming out of the computer!" Well to make a long story short this is what I found.



The computer will run off of the battery but not the AC adapter nor will it charge the battery.

Anyone know what this part is and where do I get one?

My guess it is a TVS diode but as you all probably already know ASUS will not give out any of this information.

Any help Identifying this is greatly appreciated so I can get my computer up and running again.

Thanks in advance for any reply's I get.

[lord]

Re: ASUS motherboard blown TVS diode?

I tried to find it on rthe scheme, but the picture is too small to identify the component. Here, maybe you will succeed.

[felon637]

Re: ASUS motherboard blown TVS diode?

I tried to find it on rthe scheme, but the picture is too small to identify the component. Here, maybe you will succeed.

Thank you very much!

Sorry to ask you to hold my hand but I am very new to this. I have no problem making out the schematics but have no idea what I am looking for.

I believe my component would be on page 91 of the pdf file you attached but not sure which one.

I have a revision 2.3 and the schematic is 1.1. Not sure if they would be the same or not.

Do I need to match the identifier numbers on the schematic with the numbers on the motherboard? Example "r9106" is a resistor that should be marked the same on the motherboard?

Thanks again for your help and please excuse my ignorance.

[lord]

Re: ASUS motherboard blown TVS diode?

Not sure about the revision, there could be a difference between the 1.1 schematics and 2.3 board.
Try to identify the component near the blown component and then follow the lines comparing it to the schematic until you come along your component.
Measure with multimeter resistance of blown_component_pin1 to GND and pin2 to GND.
The picture doesn't show but i thing that the blown component is connected to D of Q8804 (FDS4435BZ), and if it's true the blown component could be a capacitor connected to the GND C8805 or 8808 (page 88), and the laptop can work without it (it will not work if the blown capacitor is short).
Hope this helps!

[felon637]

Re: ASUS motherboard blown TVS diode?

lord: Okay, thanks for the direction, I am in the process of staring at it and will bring my DVOM home from work tomorrow to check the pins to ground.

[felon637]

Re: ASUS motherboard blown TVS diode?

I traced it down to J8803 which says it's a "shorting_pin" on the schematic. What the heck is a shorting pin. Aside from a pin that shorts. LOL.

Thanks

[felon637]

Re: ASUS motherboard blown TVS diode?

Borrowed my neighbors DVOM.

13ohms across the component
13ohms from one pin to ground
0 ohms from the other pin to ground

So I am assuming if it is a shorting pin it would be normally open allowing the computer to function properly.

If it received too much current or voltage it would short saving the computer from damage.

So is this just a bad part?

Is the power adapter bad? It did check fine.

Maybe the voltage spike was a one time event that won't happen again?

I removed the shorting pin and am going to reassemble the computer to see if it will run off of ac power while I wait for you guys to post as to the identification of this component.

thanks again for the help

[felon637]

Re: ASUS motherboard blown TVS diode?

Reassembled computer and still nothing. Will run off of the battery but not the power cord nor will it charge.

[lord]

Re: ASUS motherboard blown TVS diode?

This is not a shortiong pin. Shorting pin would be the orange marking on the board to the left of the label.
Try to replace U8801.

[felon637]

Re: ASUS motherboard blown TVS diode?

This is not a shortiong pin. Shorting pin would be the orange marking on the board to the left of the label.
Try to replace U8801.

What of the burn component I removed?

[felon637]

Re: ASUS motherboard blown TVS diode?

burnt I mean

[lord]

Re: ASUS motherboard blown TVS diode?

I don't understand.

[felon637]

Re: ASUS motherboard blown TVS diode?

I don't understand.

You said to replace U8801 but that is not the piece that is burnt.

Are you saying to replace that and I don't need to worry about the part that is burnt?

[lord]

Re: ASUS motherboard blown TVS diode?

The part that's burnt remove completely, and try to replace that controller. They are easily damaged.
The thing is if the blown part is a capacitor you can do without it.

[fddizon]

Re: ASUS motherboard blown TVS diode?

lord,

can i ask why diode burns? a client sent me a gateway laptop with burnt diode. i replaced the part but still the laptop did not power up.

[felon637]

Re: ASUS motherboard blown TVS diode?

The part that's burnt remove completely, and try to replace that controller. They are easily damaged.
The thing is if the blown part is a capacitor you can do without it.

Gotcha! Thanks again for all your help.

[fddizon]

Re: ASUS motherboard blown TVS diode?

felon,

did it work by replacing the diode only?

[felon637]

Re: ASUS motherboard blown TVS diode?

felon,

did it work by replacing the diode only?

Removed the diode, or capacitor or whatever it is and left it out but computer will not charge nor run off AC. Lord says it should work without that part if it is a capacitor "which he thinks it is" so my power controller is probably bad. I am working on trying to find a power controller at this time.

[rockxstar89]

Re: ASUS motherboard blown TVS diode?

I have the same problem here. I was running a third party power supply (antec 65w universal adapter) and when the girlfriend plugged it in it sparked and left a burning smell.
I took it apart to find the very same component burned out, and am pretty sure it's a TVS diode. Mine was actually charred enough the silicon blew right off and I could see its innards without the insulation.

I was running the laptop off of battery, however it was slowly dying. Didnt get a chance to run a full diagnostics, however it seemed as though it would run off ac. It was running off battery with the power cable plugged in, but it was not charging the battery, and any time I removed the power cable it shut off.

I have a friend who can do the repair work for me, but I need to know parts first.
Should the diode be replaced??? obviously it served some purpose, had some type of current running through it if it burned out the way it did.

felon have you had any luck procuring a power controller?
or getting your laptop to work for that matter??

[lord]

Re: ASUS motherboard blown TVS diode?

In the scheme there is no diode in the DC input. Maybe somebody has the mobo alive and can id the blown part?