Technical Support BQ24780S not working ACDRV

lazaro089

Registered
Golden

Reputation:

Hi I have a Lenovo Thinkpad. Board LA-c421P (no schematics or Boardview available).
The problem is that input mosfets are not driven by ACDRV.

Already changed Charger IC. Both Q1 and Q2. Checked continuity between R4 and R3. Checked C1 and C2 not shorted.
ACDET 2.6V
ACOK 3.3V
VCC 19.8V
REGN 6V

CMSRC 0.424 V
ACDRV 0.262 V

If I jump Adapter VCC @ R0 to ACP, the laptop turns on ok and stays on.

1624916243320.png
 

Hosein Asadolahi

Staff member
Registered

Reputation:

Hi I have a Lenovo Thinkpad. Board LA-c421P (no schematics or Boardview available).
The problem is that input mosfets are not driven by ACDRV.

Already changed Charger IC. Both Q1 and Q2. Checked continuity between R4 and R3. Checked C1 and C2 not shorted.
ACDET 2.6V
ACOK 3.3V
VCC 19.8V
REGN 6V

CMSRC 0.424 V
ACDRV 0.262 V

If I jump Adapter VCC @ R0 to ACP, the laptop turns on ok and stays on.

View attachment 55412
ohm check r ac . reprogram ec NPCE 388NA1DX ( you must jump vcc , acp and after do that you can reprogram ec ). if result is same you must check (ohm check of all resistors and capacity of all cap) all components around of ic charge .
 
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