Asus R503V (MB: X55VD) Strange short on chip RT8207M

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Brand: Asus
Model: R503V
Motherboard: ASUSTeK X55VD, Rev.: 2.1
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Hello!

I'm working on the mentioned laptop, which the following symptom: After pressing on the power button LEDs turns on for one second, then laptop turns off.

I found short between pins G and S of transistor (highlighted on the following picture).


I found out that the mentioned transistor is actually not shorted, but the short is probably caused by driver chip RT8207M (chip on the picture below). If I removed 0Ω gate resistor "R6" according to RT8207M datasheet schematic (schematic below) transistor is not shorted anymore, but it is short (resistance 1.2Ω) directly between pins 16 and 17 of chip RT8207M.


The strangest thing is that the short disappears, if I heat the RT8207M chip (with nearby surroundings) to about 80°C, but the short reappears again immediately after connecting the power supply (without pressing on the power button).


What I've done up to now:
a) Short circuit test between pins 16 and 17 of chip RT8207M -> result is hot chip RT8207M.
b) Chip RT8207M replaced with brand new one -> all is exactly the same like before.

Any ideas?

Anyone have any idea?

I replaced all of the ceramic capacitors near the RT8207M chip, after that the laptop works normally.

After that I measured the old capacitors, but none of them seems damaged, so I'm not sure if it was really bad capacitors, or the heat during soldering process "repairs" the board.

However I'm testing the laptop for five days now, and it does not show any issue.

I hope it will not came back after that when I returned it to the customer .