Dead ASUS ROG G14 (GA401)

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Sorry, I meant to measure the voltage to ground of each pin. Post the list again.

Need to check if the charger IC has the conditions to spit out the boosted voltage on ACDRV. Be sure that the part is well fluxed and well heated to swim but settle down on the PCB pads, naturally. Low air pressure but enough heat to make it swim. Just in case there are any shorts, this process will correct the hidden shorts.

Alright, I will remove and resolder the BQ IC and get new measurements tomorrow, it's bedtime for me

Thank you for your support!

EDIT: I also find it weird that the second mosfet did output 20V when I first replaced the BQ IC, but when I had it in the case, with display etc plugged in, nothing happened, and afterwards the mosfet measured 4V again.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Perhaps some other component is causing the main power rail to tank.

You can check the resistance to ground of the main power rail but without power of course.

Check it without the display -> then with the display. If the current sense by the charger IC is that there is an excessive current draw, the DCin mosfets will be instructed to shut off.

Do not connect the battery at this stage of testing - only the power adapter. Need to be sure that the video and normal boot cycle is working.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Perhaps some other component is causing the main power rail to tank.

You can check the resistance to ground of the main power rail but without power of course.

Check it without the display -> then with the display. If the current sense by the charger IC is that there is an excessive current draw, the DCin mosfets will be instructed to shut off.

Do not connect the battery at this stage of testing - only the power adapter. Need to be sure that the video and normal boot cycle is working.

Sorry, actually the display was not connected. The laptop was purchased with a broken display as well, so I only connected the display cable to the motherboard, the other end was not connected to a display.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Got some voltages for ya'

Wouldn't the voltage only tank if something was connected? I have everything disconnected when doing the measurements...

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Pin 10 voltage on the charger IC is of concern.

See attached.

Can you remove the 2nd DCin mosfet? Then measure the resistance of the removed part while it is on your work table.

Intered in the resistance readings of the removed mosfet between:

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

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Pin 10 voltage on the charger IC is of concern.

See attached.

Can you remove the 2nd DCin mosfet? Then measure the resistance of the removed part while it is on your work table.

Intered in the resistance readings of the removed mosfet between:

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

Just did S-D, and that measures a dead short... Jesus, these are hard to find. I did voltage injection, although only 1V1A, but still, that did not show up on the thermal image...

[mon2]

Re: Dead ASUS ROG G14 (GA401)

What are the topside markings of this mosfet?

Being n-channel, you can probably replace it with many others on donor boards, etc.

First, need to be sure there is a physical match.
2nd - the mosfet is N-channel.
3rd - current / voltage support.

If you have donor boards around - check if the charger IC is any of the BQ series. The BQ charger ICs use N-channel mosfets.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

What are the topside markings of this mosfet?

Being n-channel, you can probably replace it with many others on donor boards, etc.

First, need to be sure there is a physical match.
2nd - the mosfet is N-channel.
3rd - current / voltage support.

If you have donor boards around - check if the charger IC is any of the BQ series. The BQ charger ICs use N-channel mosfets.

It is a M3058M, I have a couple of those laying around as well

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Before you proceed..check that there are no shorts on the source, gate or drain pins on the PCB pads.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Before you proceed..check that there are no shorts on the source, gate or drain pins on the PCB pads.

No shorts on pads. Soldered new mosfet, no change. Still same 4V out, and 0V on Pin 10.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Measure the voltage to ground readings of the first mosfet.

Post each measurement.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

I also missed the low voltage on pin # 3 (CMSRC). Mosfet # 1 is a suspect.

Attached is a typical hookup of this charger IC.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Measure the voltage to ground readings of the first mosfet.

Post each measurement.

So with AC connected?

[mon2]

Re: Dead ASUS ROG G14 (GA401)

Yes, with the adapter connected.

After the voltage check, remove all power.

Measure the resistance of the same mosfet:

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

Post each measurement.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Yes, with the adapter connected.

After the voltage check, remove all power.

Measure the resistance of the same mosfet:

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

Post each measurement.

Here you go.

[mon2]

Re: Dead ASUS ROG G14 (GA401)

What is the gate voltage to ground on this mosfet with the adapter connected?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

what is the gate voltage to ground on this mosfet with the adapter connected?

0.58v

[mon2]

Re: Dead ASUS ROG G14 (GA401)

What is the voltage to ground of +RTCBAT ?

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

At the risk of being the bad guy again, I can not ignore how much effort people like mon2 and others already invested here.

In the picture of Post #34, the Charging controller is in my opinion not aligned properly.
Another example is the measurement at the low-side Mosfet for GPU_Core in Post #1 where a resistance of 200 Ohms between Source and Drain was shared although the Core resistance to GND was only 22 Ohms to GND. These values are mutually exclusive.

Just a few examples if someone wonders why here is almost no progress at all.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

At the risk of being the bad guy again, I can not ignore how much effort people like mon2 and others already invested here.

In the picture of Post #34, the Charging controller is in my opinion not aligned properly.
Another example is the measurement at the low-side Mosfet for GPU_Core in Post #1 where a resistance of 200 Ohms between Source and Drain was shared although the Core resistance to GND was only 22 Ohms to GND. These values are mutually exclusive.

Just a few examples if someone wonders why here is almost no progress at all.

I appreciate all the help I can get, I'm still very much a newbie and do this occasionally in my spare time.

The charging IC has since been aligned properly, but rest assured, I did check all the pins for bridges and connection before posting any readings.

In regards to the 200 Ohm mosfet, I did point it out to see if this could be a culprit, but honestly have no clue on how to troubleshoot it, other than thinking "This seems wrong" and posting it.