ASUS 90W Charger

[Pedroffs]

Hi all,

This charger is not working, I saw that it is a bit burned around that component. ( looks like a coil)

Any idea about how to fix this? Should I replace the component? Anyone knows exactly what it is? I don't have any reference.

Any help would be appreciated.

Thank you.

Pedro Santos

[mariushm]

Re: ASUS 90W Charger

It's a common mode choke, meant to reduce noise sent back through the power cable.

Technically, the adapter could function perfectly fine without it.
Just look on the back of the circuit board, the AC wires go through that part and into that gray rectangular capacitor, so you just have to create connection directly to that capacitor by soldering two wires in the place of that part.
Should be a wire between the two holes on the left side, one wire between the two holes on the right side, but double check by looking on the back of the circuit board.

Anyway... if that inductor burned down (a broken wire on the inductor could explain why it's not working as AC isn't going further than the part) ... it could be that some other components are dead (shorted) further in the circuit, and that short circuit may have been the cause for the inductor breaking down.

[budm]

Re: ASUS 90W Charger

Hi all,

This charger is not working, I saw that it is a bit burned around that component. ( looks like a coil)

Any idea about how to fix this? Should I replace the component? Anyone knows exactly what it is? I don't have any reference.

Any help would be appreciated.

Thank you.

Pedro Santos

Please show us good clear pictures of the bottom side of the board, the burnt may be due to cold solder joints of the inductor legs to the traces.

[stj]

Re: ASUS 90W Charger

yea, looks like it just burned at the pin.

[PeteS in CA]

Re: ASUS 90W Charger

Concur that it could be a bad solder joint. But as mariushm pointed out, there could be a problem farther on in the circuit that drew excessive current.

[CapLeaker]

Re: ASUS 90W Charger

I've seen them break off right at the top or shortly after the top of the PCB. If there is no replacement, take a winding or half a winding off that choke.
It doesn't have to be a bad circuit component, that drew excessive power... it also could be due to vibration etc.

[Pedroffs]

Re: ASUS 90W Charger

Hi Guys, thank you for the replies
Here're some better pictures.

I've just try to re-solde the that burned component but nothing changed.

Any ideia?

BR,
Pedro Santos

[stj]

Re: ASUS 90W Charger

remove the coil, clean the soot off and check it off-board.

[Pedroffs]

Re: ASUS 90W Charger

remove the coil, clean the soot off and check it off-board.

Will do, thanks.

How do I test the coil?
From 2 points of the coil I have 20MOhm resistance and the other 2 have no connectivity.
That's is probably the issue?

Should I just shunt those points?
BR,
Pedro

[budm]

Re: ASUS 90W Charger

See picture of the pinout.

[R_J]

Re: ASUS 90W Charger

It looks like the fuse is open, Check the ac voltage between A and B then check between A and C, or check the resistance between B and C

[budm]

Re: ASUS 90W Charger

I would expect OP to test the fuse already, common sense.

[eccerr0r]

Re: ASUS 90W Charger

This measurement looks suspicious:
https://www.badcaps.net/forum/attach...3&d=1555586153
That should be shorted together as a common mode choke, meaning it should be 0 volts across the two? Would imply the coil broke but I still can't believe coils break like that...

Agreed, probably could assume fuse was tested, but good to cover all bases.

In any case likely there's downstream issues unless it just so happens the coil broke... again, this is tough to believe but stranger things have happened.

--- Edit ---

Talk about the common mode coil... though it does qualify for "double insulated" ... Wow... how did this get past safety design?!?!? You don't wind/use coils like that when used for line voltage!!!

[walldog1]

Re: ASUS 90W Charger

Personally, unless I had a spare coil, I would just replace. They don't cost much and I am sure I have the one you need if interested. Just message me if you want.