Acer nitro Nitro 5 FH51M No Power

[lorins_core]

good day to all

does anyone have an idea for this problem, I trace the Short on the system board to check the used schematic diagram.

* thank satishkumar give us a schematic diagram. here is the link https://www.badcaps.net/forum/showth...87#post1136887

now the problem I trace on +3VALW

[mon2]

Re: Acer nitro Nitro 5 FH51M No Power

What is the voltage of +19VB ?

Voltage on pin 12 of pu301 ? (3V_EN)

Remove all power, meter in resistance mode.

Check the resistance to ground of +3VALWP.

[lorins_core]

Re: Acer nitro Nitro 5 FH51M No Power

What is the voltage of +19VB ?

Voltage on pin 12 of pu301 ? (3V_EN)

Remove all power, meter in resistance mode.

Check the resistance to ground of +3VALWP.

thanks i try later...

[lorins_core]

Re: Acer nitro Nitro 5 FH51M No Power

What is the voltage of +19VB ?

Voltage on pin 12 of pu301 ? (3V_EN)

Remove all power, meter in resistance mode.

Check the resistance to ground of +3VALWP.

Voltage on pin 12 of pu301 ? (3V_EN) = Answer is 0.0V

+3VALWP = Answer is 0 OHM (shorted to Ground)

[mon2]

Re: Acer nitro Nitro 5 FH51M No Power

Can you confirm the resistance scale used on your meter?

Try the next high scale on the meter.

There should be no power to the logic board with the resistance measurements.

Confirm again this resistance to ground. With a 0 ohm reading, there is a hard short on this rail.

[micsoria]

Re: Acer nitro Nitro 5 FH51M No Power

following this post. same problem with mine.

[lpraderi]

Re: Acer nitro Nitro 5 FH51M No Power

Similar problem, 0 Ohms on B+ rail (19V).

Lifted CPU VRM Phase Coils , short gone .
ID Phase3 and Phase4 Output mosfets PQ8103 and PQ8104 (AON6962)
Waiting for new ones.

Datasheets:
PCB: LA-F591P
VRM RT3607CE
MOSFET AON6962

[mon2]

Re: Acer nitro Nitro 5 FH51M No Power

Lifted CPU VRM Phase Coils , short gone .

This often means that the high side voltage of ~19v has hit the CPU and the CPU is now defective.