Dead ASUS ROG G14 (GA401)

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

What is the voltage to ground of +RTCBAT ?

Just got back from work, the RTCBAT pin measures 0V. I don't know if this is due to the laptop using the main battery as a RTC battery, but the port is left unused on these models.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

I appreciate your honesty and good to know, you sorted the question about the charging IC already. It is just, I'm pretty afraid of we're missing something important although we already stare at it.

You have replaced the charging controller a second time, correct?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

I appreciate your honesty and good to know, you sorted the question about the charging IC already. It is just, I'm pretty afraid of we're missing something important although we already stare at it.

You have replaced the charging controller a second time, correct?

We all start somewhere

No I have not replaced the BQ IC again, what should the reasoning behind that be? Do you think the second DC-In mosfet killed it again?

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

I don't know. A few pics of alle the jobs you have done on this board so far would be nice.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

I don't know. A few pics of alle the jobs you have done on this board so far would be nice.

Alright,
First I found a couple shorted caps around the BIOS chip (2 Ohm), removed it, but the short was still present. I resoldered it and injected 1V1A at one of the shorted caps, and saw the EC IC get hot. Removed the EC and found the short was gone. Ordered a new EC IC and soldered it, short was still gone.

Installed the board again, but still no sign of life.

I then replaced the BQ IC, still no life. I replaced the second DC-In mosfet, still no life.

That is pretty much what I have done.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

My suggestion would be to check both mosfets again a) for internal short and b) for unexpected short to GND at either Source, Drain or Gate. Without power of course.
Then a updated voltage measurement of the charging controller would be nice, Pin 4, 5, 6, 24, 28. Then remove power and switch to beep mode. Check any of the 28 pins for unexpected short to GND.

Then report back here

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

My suggestion would be to check both mosfets again a) for internal short and b) for unexpected short to GND at either Source, Drain or Gate. Without power of course.
Then a updated voltage measurement of the charging controller would be nice, Pin 4, 5, 6, 24, 28. Then remove power and switch to beep mode. Check any of the 28 pins for unexpected short to GND.

Then report back here

Thanks, sorry for late response.
I did some measurements, see pic.

I also changed the BQ again, no change.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Found this mosfet (source) shorting to ground now, pretty sure it didn't before though
Should I remove and measure it?

It sits under the GPU.

EDIT: Removed mosfet, short is still present on Source pad.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Injected 1V2A on the Source pad, nothing got hot on the thermal image.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

Please Stop immediately with this headless troubleshooting.

You're injecting into the low-side mosfet of GPU_Core, where one side is indeed GND and the load side "appears" as GND, because it is the GPU_CORE rail, so very low Ohms reading expected. This is absolutely normal and you're trying to kill the GPU right now.

So please just stop with what you're doing. You're on the best way to destroy the board. I didn't had time to check your measurements. I'll do it later, asap.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Please Stop immediately with these headless troubleshooting.

You're injecting into the low-side mosfet of GPU_Core, where one side is indeed GND and the load side "appears" as GND, because it is the GPU_CORE rail, so very low Ohms reading expected. This is absolutely normal and you're trying to kill the GPU right now.

0.2 Ohm low? Is that GPU_Core resistance?

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Please Stop immediately with this headless troubleshooting.

You're injecting into the low-side mosfet of GPU_Core, where one side is indeed GND and the load side "appears" as GND, because it is the GPU_CORE rail, so very low Ohms reading expected. This is absolutely normal and you're trying to kill the GPU right now.

So please just stop with what you're doing. You're on the best way to destroy the board. I didn't had time to check your measurements. I'll do it later, asap.

Alright, soldered the mosfet back.
Thanks.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

0.2 Ohm low? Is that GPU_Core resistance?

Yes, it is.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

Everything looks normal, except ACDRV not coming up. Since this component connects to ACDRV line i strongly suspect it to be the culprit here.
Are you able to trace where else it connects to?

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

Look, what i've found in the schematics of a ASUS GX531GS. Same charging IC and this extended ACDRV circuit. Maybe i'm wrong, but if this is a faulty diode, you should get ACDRV back as soon as you have removed it.

Check, try and report please.

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

Look, what i've found in the schematics of a ASUS GX531GS. Same charging IC and this extended ACDRV circuit. Maybe i'm wrong, but if this is a faulty diode, you should get ACDRV back as soon as you have removed it.

Check, try and report please.

I'll check! Thank you so much!

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

This is the one, should I remote it and connect power?
It's a transistor.

I also uploaded a screenshot of the ACDRV path...

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

This is the one, should I remote it and connect power?
It's a transistor.

I also uploaded a screenshot of the ACDRV path...

It is not a diode, but basically does the same like in previous shared schematics.

so yes, remove it and see what happens. You'll lose the overvoltage(?) protection then, ofc... but that's a secondary issue right now...

[jacobtc]

Re: Dead ASUS ROG G14 (GA401)

It is not a diode, but basically does the same like in previous shared schematics.

so yes, remove it and see what happens. You'll lose the overvoltage(?) protection then, ofc... but that's a secondary issue right now...

Alright, ACDRV is now 1.2V!
DC-in mosfets are still low, 1.2V output from the first and 4V from the second.

[Sephir0th]

Re: Dead ASUS ROG G14 (GA401)

This is so weird. Check the Mosfets again for internal short, for sanity

And then place the component back and check voltage at all three pins pls.