ASUS X712EA No power

[pc_okay]

Hello,

Little problem with this Asus board, X712EA R2.0, get no power no charge.

Tension without battery:

BQ24780s

ACN 3.2V
ACP 3.2V
CMSRC 3.2V
ACDRV 3.2V
ACOK 2.6V
ACDET - 2.7V
REGN- 6V

No schematics, i replace the chip juste to be sure.. but same problem.

Thank you for your help.

[mcplslg123]

Yes, go ahead and replace the 2nd mosfet.

[mon2]

Quite a few 3v2 measurements. That is a good clue.

Locate the DCin mosfets that should be nearby the DCin power connector and these N-channel mosfets will be driven by the ACDRV signal. Post pics and/or topside markings of these mosfets for a review.

Once you find these DCin mosfets (usually there are 2 of these) -> power down. Disconnect the battery.

Meter in resistance mode.

Measure the resistance to ground of the ACN or ACP pins. We are checking if there is a shorted component on the main power rail used to power the logic board. What is the resistance in ohms?

Next, measure 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 each measurement for each mosfet.

Summary: As per the sticky above on charger circuits by piernov, most likely you have a defective and leaky mosfet in the power path from the DCin power adapter and the main power rail.

[pc_okay]

Hello and thank you for you quick answer !

ACP/ACN 2 Million Ohm

1rst mofset m3056M

source (1-2-3) & drain (5-6-7-8) 50kohm
source (1-2-3) & gate (4) 23 ohm
gate (4) & drain (5-6-7-8) 50kohm

2nd mofset E180AJ
source (1-2-3) & drain (5-6-7-8) 0 ohm
source (1-2-3) & gate (4) 23 ohm
gate (4) & drain (5-6-7-8) 23 ohm

2nd mofset seems to be bad, don't you think?

Thanks again !

[mcplslg123]

Yes, go ahead and replace the 2nd mosfet.

[pc_okay]

Hello everybody !

I replace the second mofset and now laptop working is fine.
I will not forget the sticky.

Thank you again.