ASUS ROG G14 (GA401) battery spark, dead.

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Does the logic board function without the battery ? It should.

If it does not, the battery is not a factor. For now, work without the battery.

You can inspect the SMBUS (I2C) lines on the battery connector.

Remove all power. Meter in resistance mode.

Check the resistance to ground of the following:

P_SMB0_CLK - pin 3
P_SMB0_SDA - pin 4

Red meter lead on the pin; black to ground.

What are the resistance readings for each ?

[Stevedb]

Re: ASUS ROG G14 (GA401) battery spark, dead.

What is board number ?

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

ACDET is a good voltage.

See attached. Confirm that the VCC pin is being fed a proper voltage for the charger IC.

Confirm the voltage of ACOK status. Check & post the voltage.

VCC on charging IC is 19.7V

ACOK is fed 6V.

Could it be a defective shorted battery? Voltage measures 0V on the battery, but it worked before, so maybe some internal protection got triggered?

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

ACDET is a good voltage.

See attached. Confirm that the VCC pin is being fed a proper voltage for the charger IC.

Confirm the voltage of ACOK status. Check & post the voltage.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Ok. This will be a painful one. I found some but from a paid service. Let me post some partial screen grabs.

The BV file is horrible but may work.

See attached.

Thank you, PR8904 are at 2.7V

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Ok. This will be a painful one. I found some but from a paid service. Let me post some partial screen grabs.

The BV file is horrible but may work.

See attached.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Do you have schematics for this logic board ?

No I don't.

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Do you have schematics for this logic board ?

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

What is the resistor value from current resistorr010 to ground. also the resistor value from the mosfet D-G , S-G en D-S from the mosfet and nearby the current resistor.

And also the one you replaced. Maybe they got bad again.

Current resistor to ground is around 3 Mohm.

The M3058M mosfet to R010:
Drain: 0.8 Mohm
Source: 0 ohm
Gate: 2 Mohm

D-G: 2.4 Mohm
S-G: 1.9 Mohm
D-S: 1.1 Mohm

The new mosfets also have high values, nothing low.

[Stevedb]

Re: ASUS ROG G14 (GA401) battery spark, dead.

What is the resistor value from current resistorr010 to ground. also the resistor value from the mosfet D-G , S-G en D-S from the mosfet and nearby the current resistor.

And also the one you replaced. Maybe they got bad again.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

When performing the voltage checks, remove the battery so we can check how far the power adapter travels onto the logic board. The logic board should function with only the power adapter.

Measured on the mosfets along the way from the DC-in. Hope you can read the values, they were drawn on my phone

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

When performing the voltage checks, remove the battery so we can check how far the power adapter travels onto the logic board. The logic board should function with only the power adapter.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Resistance checks are always to be performed WITHOUT power.

Remove the power adapter and remove the battery.

Measure again.

The resistance checks were done without power

Only the voltage checks were done with power.

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Resistance checks are always to be performed WITHOUT power.

Remove the power adapter and remove the battery.

Measure again.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Also the measurements are with battery present i hope?

Also measure the resistance to ground on the pins what @mon2 said that are not good.

Good luck we will fix your laptop.

Yes, meassurement were done with AC and battery connected

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

You may have a leaky high side mosfet. Locate the mosfets linked to the battery charging - there will be 2 of them. One for HIGH SIDE; One for LOW SIDE.

1) Post the markings on the top side for a review.

2) From the datasheet of the charger IC, these will be N-channel mosfets. So much like the ACDRV signal, the LODRV and HIDRV mosfets must have their GATE voltage ~6 volts higher than the voltage they are passing between SOURCE & DRAIN pins to enable and turn ON the mosfet.

3) Let us check if these mosfets are shorted / defective. Remove all power. No battery. Wait 30 seconds or so to discharge any potential voltage on the logic board.

Multimeter in resistance mode (start with the lowest scale).

Check the resistance across the mosfet pins as follows:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post the readings for the each mosfet - low side & high side. Also post the scale on your meter used for the measurements.

If you see a '1' on the meter, this means the resistance is higher than the meter scale so switch to the next higher scale.

A low resistance reading = defective mosfet. Mosfets are inexpensive and usually < $ 1 USD each so recommend to replace both mosfets and even consider to buy spares.

We usually buy the mosfets from Aliexpress unless there is a rush. If in a rush, consider to buy from Digikey / Mouser / Arrow or a local electronics distributor. Once we know the markings, other parts can be used a replacement.

The next mosfet to investigate is the BATTERY mosfet which will be linked to the charger IC, pin # 18 => will be connected to the gate (pin # 4) of the mosfet. Search for it and also check the resistance as above.

When and if buying replacement parts, order 1 or few of these as well.

Given the incorrect readings for the LODRV and HIDRV, consider to also check the resistance to GROUND for these pins on the charger IC. That is, if these pins were shorted during the soldering, etc., this can cause the low readings. Also, if the pins are not connected at all from the charger IC to the mosfets, you will see the similar readings.

Post your updates.

1) I guess these are the ones I already replaced, see first picture. They both read in the Mohm/kOhm range, so I guess they are good?

3) See 1.

The battery mosfet is the one in picture 2, and shows 0.27ohm from gate to pin 18 on charging IC. This is the only mosfet I haven't replaced on the right side of the board

LODRV and HIDRV both show high resistance (Mohm/kOhm) to ground.

[Stevedb]

Re: ASUS ROG G14 (GA401) battery spark, dead.

Also the measurements are with battery present i hope?

Also measure the resistance to ground on the pins what @mon2 said that are not good.

Good luck we will fix your laptop.

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

batpres = 0v ; good
lodrv = 0v ; not good
hidrv = 0.223v ; not good
srn = 0.223v ; not good ? (matches hidrv)
srp = 0.223v ; not good ? (matches hidrv)

EDIT: ACDRV is 26V ; good

You may have a leaky high side mosfet. Locate the mosfets linked to the battery charging - there will be 2 of them. One for HIGH SIDE; One for LOW SIDE.

1) Post the markings on the top side for a review.

2) From the datasheet of the charger IC, these will be N-channel mosfets. So much like the ACDRV signal, the LODRV and HIDRV mosfets must have their GATE voltage ~6 volts higher than the voltage they are passing between SOURCE & DRAIN pins to enable and turn ON the mosfet.

3) Let us check if these mosfets are shorted / defective. Remove all power. No battery. Wait 30 seconds or so to discharge any potential voltage on the logic board.

Multimeter in resistance mode (start with the lowest scale).

Check the resistance across the mosfet pins as follows:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post the readings for the each mosfet - low side & high side. Also post the scale on your meter used for the measurements.

If you see a '1' on the meter, this means the resistance is higher than the meter scale so switch to the next higher scale.

A low resistance reading = defective mosfet. Mosfets are inexpensive and usually < $ 1 USD each so recommend to replace both mosfets and even consider to buy spares.

We usually buy the mosfets from Aliexpress unless there is a rush. If in a rush, consider to buy from Digikey / Mouser / Arrow or a local electronics distributor. Once we know the markings, other parts can be used a replacement.

The next mosfet to investigate is the BATTERY mosfet which will be linked to the charger IC, pin # 18 => will be connected to the gate (pin # 4) of the mosfet. Search for it and also check the resistance as above.

When and if buying replacement parts, order 1 or few of these as well.

Given the incorrect readings for the LODRV and HIDRV, consider to also check the resistance to GROUND for these pins on the charger IC. That is, if these pins were shorted during the soldering, etc., this can cause the low readings. Also, if the pins are not connected at all from the charger IC to the mosfets, you will see the similar readings.

Post your updates.

[jacobtc]

Re: ASUS ROG G14 (GA401) battery spark, dead.

see attached.

1) as per @stevedb, what is the voltage of pin # 15 (batpres#) ?

This is an active low signal so if a low voltage then a battery is present and will be detected by this charger ic.

2) voltage readings on the following pins ?

Pin 23 (lodrv)
pin 26 (hidrv)

pin 19 (srn)
pin 20 (srp)

batpres = 0v
lodrv = 0v
hidrv = 0.223v
srn = 0.223v
srp = 0.223v

EDIT: ACDRV is 26V

[mon2]

Re: ASUS ROG G14 (GA401) battery spark, dead.

See attached.

1) As per @Stevedb, what is the voltage of pin # 15 (BATPRES#) ?

This is an ACTIVE LOW signal so if a LOW voltage then a battery IS present and will be detected by this charger IC.

2) Voltage readings on the following pins ?

pin 23 (LODRV)
pin 26 (HIDRV)

pin 19 (SRN)
pin 20 (SRP)