Ask Samsung XE700T1C - Dead after polarity inverted in charger

[ploty1]

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Hi.
This is my first time asking help here (im from Portugal).

I reveived this laptop dead.
The polarity of charger was inverted and pluged in. The laptop dosent kill instalntlly, but after battery drein (15 min after), laptop shut down, and now dosent power or charge or blink.
I read in internet and more people have same problem in another forum and they suspect "TPS2421-2".
Can someone point me correct direction please? my VIN of u521 dosent have 12v



here is full charger dc in. what burn first after polarity inverted from 12volts charger ?

 

[ThienBui]

Hardware problems are hard to diagnose over the internet
need to check each component directly

 

[ploty1]

Ok. I Guess found solution. MOSFET q38 shorted. But fet is aon7200. May i use 9402gyt? Can someone confirm please

 

[ploty1]

ok. i found solution.
mosfet q38 shorted.
is a aon7200. you can replace by 9402gyt. now is power on without battery and with battery inside.
in my case, bq735 was not afected.