820-3462 not charging the battery

[Sr. Robot]

Hi, got a 820-3462 that is not taking charge from the battery or charging the battery correctly.

If the laptop is shutdown it charges the battery very slow, about 10% per several hours, and even if the battery is charged it will shutdown if charger is disconnected.

Tried known working battery, no change. The battery contacts are good and clean. Charger is OEM 87w

SDA/SCL lines are 0.470 on diode mode.

PPBUS_G3H without battery connected is 12.53v

 

[2informaticos]

The battery screw is tightened enough?

 

[Sr. Robot]

yes, its tightened to the max

 

[2informaticos]

Can you test if SYSDET_3_4 is really grounded?

 

[Sr. Robot]

Yes, SYSDET_3_4 is really grounded

 

[2informaticos]

Check resistance (ohm scale) between pins 17/18 and 27/28 of U7000.

 

[Sr. Robot]

17 and 18 is 3.7ohms
27 and 28 us 20.6ohms

 

[2informaticos]

What appears into system report, about battery?

 

[Sr. Robot]

It shows everything:
Full cap mah: 6669
Cycle count: 1
Condition Normal
Battery Installed: yes
Amperage: 934
Votalge: 10243

 

[2informaticos]

Try changing SMC...

 

[Sr. Robot]

Replaced SMC, no change.

 

[2informaticos]

"SDA/SCL lines are 0.470 on diode mode"
Check if voltage is correct also.

 

[Sr. Robot]

They are both 3.4v but pulse down to 3.3v

 

[Sr. Robot]

PPBUS_G3H_R and PPVIN_G3H_P3V42G3H are both 1.1v and going down with only battery connected.

R6905 is 10ohms and has continuity.


Q7055 voltages with battery and charger:
CHGR_BGATE= 2.5v
PPVBAT_G3H_CHGR_R = 10.2v
PPVBAT_G3H_CONN = 10.2v

PPBUS_G3H with battery connected is 10.2v (without battery is 12.5v)

 

[2informaticos]

"PPBUS_G3H_R and PPVIN_G3H_P3V42G3H are both 1.1v and going down with only battery connected"
Bad battery, broken trace, or battery doesn't get correct activation.