LA-G07FP ACIN signal missing

[madura2010]

10th generation hp laptop(LA-G07FP motherboard) missing ACIN signal.charger light not blow.when pressing power button, only 3 blinks display on dc adapter bulb(only once).but not turning on.original hp charger attached.charging port perfect.

19v (gate 25v) main power rail ok
RTC section ok.
3vldo ok
5vldo ok.
ECON missing.no 3v and 5v always voltage.
REGN,ACDET perfect.but ACIN missing.No short in ACIN path(good impedence)

Replaced the bq24725a charger ic.but no result.still ACIN not generating.

is this sort of error occurs from EC bios?what should i check further to fix ACIN signal.?

I would be much grateful to you if you could help me regarding this issue

[mon2]

Re: LA-G07FP ACIN signal missing

Link or post the schematic. Unable to find the ECON netname in the schematic I have. Also where does ACIN signal originate?

[gs84]

Re: LA-G07FP ACIN signal missing

did you try another original charger or hp 3 pin adapter like this?

[madura2010]

Re: LA-G07FP ACIN signal missing

i have tried with the other hp charger with adapter id.still problem persist

[madura2010]

Re: LA-G07FP ACIN signal missing

https://www.badcaps.net/forum/attach...6&d=1654389965

schematic of LA-G07FP.Here i have mentioned "ACOK" as "ACIN"

ACOK signal origiantes from Bq24725a charger ic and goes to super io(KB9022QD)l

ECON should be corrected as EC_ON.

[mon2]

Re: LA-G07FP ACIN signal missing

There will be required pull-up resistor on ACOK / ACIn pin since this is an open drain (also known as open collector) output.

What is the voltage to ground of the other side of this pull-up resistor?

With a logic low on this charge pin, the AC adapter is NOT OK.

[madura2010]

Re: LA-G07FP ACIN signal missing

"PRB15" resistor side "1" shows +3VL=3.3v.

side "2" of that resistor shows "0V"

what should i do?I have tried another charger too.should i want to try any other charger also to test whether it is a charger fault?

[mon2]

Re: LA-G07FP ACIN signal missing

Review the voltage of pin # 6 = ACDET.

What is the voltage to ground of this pin ? If this voltage is too low, the adapter will be deemed as not worthy to power this logic board.

Next, remove all power. Meter in resistance mode.

Measure the resistance across PRB17.

Measure the resistance across PRB21.

Post each reading.

[madura2010]

Re: LA-G07FP ACIN signal missing

ACDET voltage =2.7V

PRB17 412kilo ohm

PRB21 66kilo ohm

[mon2]

Re: LA-G07FP ACIN signal missing

Look like good readings.

Focus on the EC. North of the UK1 symbol in the schematic are the power pins for this component.

Measure the voltage to ground of each such pin. Post each measurement.

In following the power sequence chart on page #5, the EC_ON should be high next, if this component is being powered and has valid firmware. This device has an internal 8051 microcontroller core that requires firmware to sample the GPIO pins and to drive the EC_ON function.

[madura2010]

Re: LA-G07FP ACIN signal missing

EC_ON is 0V.
Super io all power pins recieve around 3.3Volts.

[mon2]

Re: LA-G07FP ACIN signal missing

I think the very first requirement for the RTC is being met?

What is the voltage to ground of EC_RST#? It should be a logic high to allow for the KB9022 to run.

The firmware appears to be held inside uc2 flash. Is it being powered? Check each pin on this spi flash chip.

After these checks, to me, the KB EC controller is a suspect.

Do wait for other comments but the EC controller may be with corrupt firmware.

[madura2010]

Re: LA-G07FP ACIN signal missing

thanks a lot for your attention.