A2992 no battery charging

[defdjamel]

i am completely stuck on this board , who not charging battery(battery tested ok in other logic board).
SMBUS_BATT_SDA, SCL : 1.8V no oscillation. diode 0.5
SYS_DETECT_L = 0V
CHGR_RST_IN 0V
DISP = 0V
ppvbat_AON 12V

pulup resisiatnce SMBUS_BATT_SCL./SDA : 3.3Kohm
I2C_SMC_PWR_SCL /SDA = 1.2V no oscillation ,
UD102 changed
battery connector are ok
i am stuck .
if you have an idea...

[mon2]

Has the LCD been replaced or is the original? Do you have True Tone feature?

[defdjamel]

thanks for your reply , lcd has not been replaced , but logic board is not connected to any screen during the test. charging battery not need screen.

[mon2]

Earlier this year - the Mx series had a LCD fault where the replacement screens would cause the charging to fail. Attach the LCD to test if the issue is resolved while using the display.

[defdjamel]

thanks i will check that today.

[defdjamel]

And regarding my voltage measurements, is there anything bad?
CHGR_RST_IN 0V is normal ?

[mon2]

Test the voltages on U7440 (Silego component).

Is there PP1V8_AON on U7440, pin #1 ?

Does PMU_ONOFF_L pulse when the ON/OFF button pads are shorted? Then confirm the same for PMU_ONOFF_R_L.

The output of CHGR_RST_IN (pin 10 on U7440) should also pulse with this activity. Follow the pulsing to the output of PMU_SHDN signal.

To me, this is the ON/OFF logic board signal path.

[defdjamel]

hi , i already investigate U7440 .
i have changed the component.
here measurement:
PP1V8_AON = 1.8V
PMU_ONOFF_L : 1.8 v and pulse at power ON/OFF
PMU_ONOFF_R_L : 1.8v and pulse during off
CHGR_RST_IN = 0V and no pulse.
PMU_SHDN = 0V and no pulse.
i will resolder u7440

[defdjamel]

i make a mistake on my measurement on PPVBAT_AON : 1V with small oscilation to 0.5V.
PPVBAT_AON_CHGR_R = 12V
CHGR_BGATE = 12V
CHGR_BGATE need to be 0V for mosfet Q5265

[defdjamel]

I2C_SMC_PWR_1V8_SCL / SDA were stuck at 1.8 V with no oscillation.
I checked I2C_SMC_PWR_SCL / SDA before UD102 → 1.2 V with small oscillation.
I connected the oscilloscope and saw signal activity on I2C_SMC_PWR_SCL, but nothing on I2C_SMC_PWR_1V8_SCL / SDA.
After replacing UD102 driver, now it works correctly and the battery is charging.
another tricky board brought back to life! 💪😎

[mon2]

You had replaced UD102 mentioned in the first post. It was replaced again or just needed a reflow?

[defdjamel]

right , i have replaced ud102 , without checking the oscilation on SCL, only SDA , chip was not working on SCL or bad soldering.
i have check second time and see the communication problem.
thanks for you reply. this board got a big liquid damage on keyboard , trackpad connector ,battery was shorted and dead.
now everything is working.