HP dk15-1005nc - Bad +3VL rail

[petr.hlavacu]

Hi, i have HP dk15-1005nc (mobo LA-J641P). The battery was accidentally plugged in with the opposite polarity and since then the laptop cannot be switched on. I repaired short in charger circuit, then i discovered bad PU301 (SY8288).
After the replacement I found that after connecting +3VL to the LDO pin (PJ303 on the board) the LDO switches off immediately. If I leave the contact disconnected, 3.3V for +3VL normally comes from LDO.
I have tried injecting voltage directly into +3VL with LDO disconnected and the draw is about 0.2A, nothing on the board heats up. The resistance of +3VL is in kOhms - no short.
Does anyone know where the fault may be?

[mon2]

In your testing, what is the voltage to ground of ENLDO_3V5V? This is the ENABLE signal used to enable / disable the same +3VL LDO rail.

[petr.hlavacu]

In your testing, what is the voltage to ground of ENLDO_3V5V? This is the ENABLE signal used to enable / disable the same +3VL LDO rail.

Its around 4,5V.

[mon2]

This enable is ok to keep this LDO on. When the LDO turns OFF, does this ENABLE signal remain @ ~4v5? (or does it turn off?)

[petr.hlavacu]

This enable is ok to keep this LDO on. When the LDO turns OFF, does this ENABLE signal remain @ ~4v5? (or does it turn off?)

Problem solved. The accelerometer (U9) was faulty. I tried again injecting voltage to +3VL, the current went up to 0.3A and at that point it was already visible on the thermo. Interesting that it was not visible in the previous case. After disconnecting it from the board, the laptop works without problems. Thanks for your help anyway.

[mon2]

Well done! The updates are appreciated.