Dead ASUS ROG G14 (GA401)

[InFlames]

Hello
I have an similar laptop and am facing the same issue. Were you able to fix it?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

This is not how you test a Mosfet for internal short between all three logics. But 25V at Gate points to there is possibly something else going on.

I know, both mosfets has been off and measured between S-D, G-D and G-S

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

This is not how you test a Mosfet for internal short between all three logics. But 25V at Gate points to there is possibly something else going on.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

This is a classical behaviour of a shorted DC-IN Mosfet, between Source and Drain, for example

Both DC-IN mosfets show normal behavior, 20V on S and D, 26V on G.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

See attached. Locate these local pull-ups for this SMBUS pair of lines.

Confirm the voltage on each side of the pull-up resistors.

R3001
R3015

Thanks, the boardview is not the correct one, but I found one elsewhere, these are the resistors and their measurements (see pic).

[mon2]

Re: Dead ASUS ROG G14 (GA401)

See attached. Locate these local pull-ups for this SMBUS pair of lines.

Confirm the voltage on each side of the pull-up resistors.

R3001
R3015

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

These are open drain pins so they must have local pull up resistors to park these pins to a soft logic high level.

Either these pins are missing these pull ups or the ESD diodes are pulling these pins low.

Locate the ESD diodes on these pins on the logic board. They should be fluxed and carefully removed. Do not lose the parts.

Then power up again and check these pins.

See attached for their component names.

Both are still 0.6V after removing diodes.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

These are open drain pins so they must have local pull up resistors to park these pins to a soft logic high level.

Either these pins are missing these pull ups or the ESD diodes are pulling these pins low.

Locate the ESD diodes on these pins on the logic board. They should be fluxed and carefully removed. Do not lose the parts.

Then power up again and check these pins.

See attached for their component names.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Remove the battery. Using only the power adapter, what are the voltage readings to ground of these 2 pins?

Both are 0.6V

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Remove the battery. Using only the power adapter, what are the voltage readings to ground of these 2 pins?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

This is in diode mode?

Place meter now in dc volts mode.

What is the voltage to ground with the battery and adapter connected for these smbus pins (SCL and SDA)?

No, DC mode

[mon2]

Re: Dead ASUS ROG G14 (GA401)

This is in diode mode?

Place meter now in dc volts mode.

What is the voltage to ground with the battery and adapter connected for these smbus pins (SCL and SDA)?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

My bad, yes pins #4 & 5 which appear to be ok for the diode mode readings.

Let us check that the contacts reach the charger IC.

Meter in diode mode. Short the meter probes and you should have a tone beep.

One meter probe on pin #4 of the battery connector (without the battery connected); other meter probe to pin #12 on the charger IC.

Do you hear a tone beep?

Repeat with pin #5 of the battery connector & pin # 11 on the charger IC.

After the above tests, power up - still without the battery.

Meter in DC volts mode. Measure the voltage to ground on pins #4 & #5 on the battery connector.

You should have ~3v on each SMBUS SCL / SDA pin.

Finally, connect the battery again and check if the voltage to ground measurements remain at ~3v on these battery contacts.

A defective BMS board on the battery pack can cause the SMBUS communication to fail. At that point, the battery should be replaced.

Post each measurement.

Connection between connector and IC is there.

Both pin #4 and #5 show only 0.66V when DC in connected and pc turned on, also with battery plugged in.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

My bad, yes pins #4 & 5 which appear to be ok for the diode mode readings.

Let us check that the contacts reach the charger IC.

Meter in diode mode. Short the meter probes and you should have a tone beep.

One meter probe on pin #4 of the battery connector (without the battery connected); other meter probe to pin #12 on the charger IC.

Do you hear a tone beep?

Repeat with pin #5 of the battery connector & pin # 11 on the charger IC.

After the above tests, power up - still without the battery.

Meter in DC volts mode. Measure the voltage to ground on pins #4 & #5 on the battery connector.

You should have ~3v on each SMBUS SCL / SDA pin.

Finally, connect the battery again and check if the voltage to ground measurements remain at ~3v on these battery contacts.

A defective BMS board on the battery pack can cause the SMBUS communication to fail. At that point, the battery should be replaced.

Post each measurement.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

This is a classical behaviour of a shorted DC-IN Mosfet, between Source and Drain, for example

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

This thread has 6 pages already and I have no idea anymore what was tested and what not. So my suggestion is to test the DC-IN Mosfets (again)...

The board does get power though, it turns on, but battery is not recognized correctly

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Good point. Forgot some models hardstrap the battery present pin to ground. Thanks.

Remove the battery and power adapter.

Meter in diode mode.

Red meter probe, yes red to ground.
Black meter probe to point to test.

We are interested in the diode mode readings of pin #3 and pin #4 of the battery connector. Again, disconnect the battery during these checks.

Pins #3 & #4 are the smbus SCL and SDA pins on the battery. We are checking if the ESD diodes at D5902 and D5903 are ok or if there are damaged from an ESD transient event.

Do you mean Pin #4 & #5? Pin #3 is a BAT+ line.

Pin #4 (CLK) reads OL
Pin #5 (DAT) reads 0.5V

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

This thread has 6 pages already and I have no idea anymore what was tested and what not. So my suggestion is to test the DC-IN Mosfets (again)...

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Good point. Forgot some models hardstrap the battery present pin to ground. Thanks.

Remove the battery and power adapter.

Meter in diode mode.

Red meter probe, yes red to ground.
Black meter probe to point to test.

We are interested in the diode mode readings of pin #3 and pin #4 of the battery connector. Again, disconnect the battery during these checks.

Pins #3 & #4 are the smbus SCL and SDA pins on the battery. We are checking if the ESD diodes at D5902 and D5903 are ok or if there are damaged from an ESD transient event.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

On some boards it is pulled to GND by factory