Asus k52f short

[Stevie2001]

UM6K1N



Bought used k52f mb from ebay was told its working.
Bought new psu board for it.
Plugged it in and thats what happened.

Why is the jmc251 ic frying.
And the 6 leg n channle mofset


https://cdn.badcaps-static.com/pdfs/...c46783c0ed.pdf
FDMC8884 N-Channel PowerTrench® MOSFET - Octopart

well by looking at boardview the 6-leg n-channle mofset tracks me to this ic witch is 5v

[SMDFlea]

Re: Asus k52f short

You bought it as working,get a refund if you can, cut your losses on it.

[Stevie2001]

Re: Asus k52f short

You bought it as working,get a refund if you can, cut your losses on it.

it costed 20 quid for mb and psu cost 20.

anyways the FDMC8884 can that be cause or should i test,am just wondering why will it fry the ethernet controller on psu board.
what i need help with is to know witch pin on j6801 i should try and inject voltage or amps to find heated shorted part on mb.

j6801 +5v pin-29 ?
boardview added to attachment

[SMDFlea]

Re: Asus k52f short

Use this schematic as reference . Check all power rails for short. KBC could be damaged too,might be ok with a good clean up. Don`t use a bench psu just yet ,look at the board, see the damage,check power rails, check what each burnt chip connects to, take them off see if the short goes you need to replace them anyway.

[Stevie2001]

Re: Asus k52f short

Use this schematic as reference . Check all power rails for short. KBC could be damaged too,might be ok with a good clean up. Don`t use a bench psu just yet ,look at the board, see the damage,check power rails, check what each burnt chip connects to, take them off see if the short goes you need to replace them anyway.

because i connected the dc adapter it did this damage so using dc power supply i can limit the amp less them 1 and set to 10v maybe to se what heats up removving the jmc ic as it is burnt now.

i will do what you said i cannot check power rail voltage without power being injected in?

the j6801 cannot be searched in pdf

[SMDFlea]

Re: Asus k52f short

Unplug the Bench PSU and forget about it. The motherboard has obvious liquid damage, why did it damage a working dc input board ? .Check on the boardview/schematic what pins the dc board connects to, then check each one of those pins on the motherboard for short to ground. And also check your charger with a multimeter,is it supplying the correct voltage,are you using the right one .

[Stevie2001]

Re: Asus k52f short

Unplug the Bench PSU and forget about it. The motherboard has obvious liquid damage, why did it damage a working dc input board ? .Check on the boardview/schematic what pins the dc board connects to, then check each one of those pins on the motherboard for short to ground. And also check your charger with a multimeter,is it supplying the correct voltage,are you using the right one .

Hi thanks.

The laptop accepts 19v input and i have universal adapter same voltage works on other lappy so am guessing adapter is ok.
Your right tho i can se signs of liquid spilages cleaned with iso all over.
This MB the old one did the exact same thing and now again on psu board and mb.

I will look for shorts now.

i will test the pins for short to gnd ignoring the gnd pins.

this jack J6801 not found in shematics when i searched.


pin-13 connects to
SCHOTTKY BAT54AW SOT-323 PHILIPS to pin1
EMBEDDED CONTROLLER IT8570E ITE LQFP-128L REV.A connects to pin17
RES A 10K OHM (0402)5% 4R8P CYNTEC/RS4N-1002-J2N pin6

pin 15 connects to
EMBEDDED CONTROLLER IT8570E ITE LQFP-128L REV.A pin-125
RES A 10K OHM (0402)5% 4R8P CYNTEC/RS4N-1002-J2N pin4


pin24 connects to
LED YELLOW GREEN SMD LITE-ON/LTST-S110KGKT pin2
N-MOSFET UM6K1N UMT6 ROHM pin3

[SMDFlea]

Re: Asus k52f short

"This MB the old one did the exact same thing and now again on psu board and mb."

What did the exact same thing,what do you mean ?

"The laptop accepts 19v input and i have universal adapter same voltage works on other lappy so am guessing adapter is ok"

What voltage is the adapter set to .

[Stevie2001]

Re: Asus k52f short

"This MB the old one did the exact same thing and now again on psu board and mb."

What did the exact same thing,what do you mean ?

"The laptop accepts 19v input and i have universal adapter same voltage works on other lappy so am guessing adapter is ok"

What voltage is the adapter set to .

"This MB the old one did the exact same thing and now again on psu board and mb."

i got the laptop second hand of a person opened it powered the unit on and the jmc ethernet controller got fried along with the 6 leg ic UM6K1N.
so this is why i went on ebay to buy another same board and they claimed it was all ok, and the psu board was new from ebay assuming its working so i assembled the psu and mb and connected adapter the led started to flicker but then smoked on the ic thats about it.4

as said about its done the same thing,i got the lappy opened it connected and got fried,ordered new mb and psu got fried.
this adapter is 19v and its ok.

maybe am shit out of luck got scammed on ebay and now i am left with the same problem i had in 1st,best i try narrow down the problem as mentioned in post 7

adapter has worked on other brand of laptops asus,acer,hp
this laptop handles 19v dc
i have adapter set to 19v

[SMDFlea]

Re: Asus k52f short

So, you used the new dc in board with the new motherboard , you didn`t try the dc in board with the old motherboard ? . And you`ve tested the adapter ,and its putting out 19V .

[Stevie2001]

Re: Asus k52f short

So, you used the new dc in board with the new motherboard , you didn`t try the dc in board with the old motherboard ? . And you`ve tested the adapter ,and its putting out 19V .

The laptop power spec is 19v
So 19v adapter is ok to use.

The old mb has been damaged so i ordered new one and the psu board.

I think it might be ITE ic look at post 7.
Is it ok to use ITE from anotherboard?

[SMDFlea]

Re: Asus k52f short

So you havn`t tested your adapter to see how much voltage at the tip...

I asked you did you use the new DC-IN board with the old motherboard, if you did thats why the IC on the DC-IN board got fried again.
If you only used the DC-IN board with the new motherboard and the IC fried then your charger might be putting out more than 19 volts,even if it is on the 19V switch , or the DC-IN board is coming into contact with something, e.g. liquid spill,shielding bent over or sticking up etc .

[Stevie2001]

Re: Asus k52f short

So you havn`t tested your adapter to see how much voltage at the tip...

I asked you did you use the new DC-IN board with the old motherboard, if you did thats why the IC on the DC-IN board got fried again.
If you only used the DC-IN board with the new motherboard and the IC fried then your charger might be putting out more than 19 volts,even if it is on the 19V switch , or the DC-IN board is coming into contact with something, e.g. liquid spill,shielding bent over or sticking up etc .

Check post 7 image and text this is why its getting fried.
Like i said am thinking ITE may be bad or partswithin that line.

Is it safe to replace ITE from different board or does it need flashing

[SMDFlea]

Re: Asus k52f short

ok.... so i`ve looked again at the images and text on post #7 .

"same voltage works on other lappy so am guessing adapter is ok"

So have you tested the charger voltage or still just guessing its ok.

The image on post #7 ,which motherboard is that, the new one or the old one .

[Stevie2001]

Re: Asus k52f short

ok.... so i`ve looked again at the images and text on post #7 .

"same voltage works on other lappy so am guessing adapter is ok"

So have you tested the charger voltage or still just guessing its ok.

The image on post #7 ,which motherboard is that, the new one or the old one .

Tested the adapter voltage
18.9v
18.8v
19.v
Jumps seems ok?.

The picture you se is new mb.

I managed to track the shorted pin and it leads strait to the io ic should i change it.

IT8570E
1102-AXA
DCE21E

[Stevie2001]

Re: Asus k52f short

Update removed

IT8570E 1102-AXA DCE21E
ITE ic
And the short from pins from post-7 is gone.
Now i managed to salvage another ITE ic from a different board however i messed up the legs got bent so il need to order new one and try it.
Do i need to get the this modle type or will any ITE ic work?

I need good flux the one i used leaves some black marks beteen pins confuses me not knowing if its solder or flux.

[SMDFlea]

Re: Asus k52f short

The IT8570E AXS or AXA . KBC chips aren`t always interchangeable,you have to check.

[Stevie2001]

Re: Asus k52f short

The IT8570E AXS or AXA . KBC chips aren`t always interchangeable,you have to check.

I ordered the AXA version.
How come it wont work.
What can i do

[SMDFlea]

Re: Asus k52f short

The AXA version youve ordered will work. While you`re waiting for that to arrive check the rest of the board for any damage.Some corroded parts will clean up with flux and new solder. Any burnt parts want replacing.

[Stevie2001]

Re: Asus k52f short

The AXA version youve ordered will work. While you`re waiting for that to arrive check the rest of the board for any damage.Some corroded parts will clean up with flux and new solder. Any burnt parts want replacing.

Can you recommened me good flux i want the ones so that even i touch the pins of ic with soldering iron the ic pins solder should split apart making each solder join up with each pin as you slide through it.

My bad experince is ic pins gets joined up with solder and have to mess about alot to get them apart i want good flux to make this job easier