820-2936 water damaged, battery not detected

Dewanbd

Member
It was water damaged. closed to ISL, changed it and worked fine except battery not detected. Found
R5280=3.4V both side, R5281=3.4v both side. Checked BIL looks good. Any help please.
 

2informaticos

Administrator
Staff member
Check traces and solders for pins 10/11 of ISL6259.
Post resistance to ground at SCL/SDA lines of battery bus.
Also post exact voltage for PPBUS_G3H.
 

Dewanbd

Member
traces and solders for pins 10/11 of ISL6259. looks good.
resistance to ground at SCL=.455 and sdl=.456
exact voltage for PPBUS_G3H=12.4 v .Thanks.
 

2informaticos

Administrator
Staff member
Bad SMC, or battery in this case.
I would test a known good battery first.
Also recommend you try another ISL6259.
Last solution, change the SMC...
 

2informaticos

Administrator
Staff member
Yeah, something happened when you changed ISL6259.
Check all solders and be sure didn't knock off any component.
Post volatge for pins 1, 2, 3, 12, 13, 14, 9, 15, 19, 20, 28.
Check resistance between pins 17/18 and 27/28 (ohm mode).
 

Dewanbd

Member
Checked all solders looks very good and no missing any components.
Voltage of ISL
pin1=0v
pin2=16.58v
pin3=3.95v
pin9=0v
pin12=1.1v
pin13=0.8v
pin14=0.8v
pin15=0v
pin19=5v
pin20=5v
pin28=16.46v

Registance ( ohm mode) betw pins 17/18=2.9 ohm
Registance ( ohm mode) betw pins 27/28=20 ohm
 

Dewanbd

Member
Volteges for U6990:
PIN9 P3V42G3H=1.1V
PIN8 P3V42G3H_FB= 4.9V
PIN7 PPVIN_G3H_P3V42G3H=16.6V
PIN6 P3V42G3H_SW=1.1V
PIN4 PPVIN_G3H_P3V42G3H=16.6V
PIN3 P3V42G3H_TON=11/12 NOT STABLE
PIN2 P3V42G3H_FB=4.9V
 

2informaticos

Administrator
Staff member
Check resistance to ground (diode mode) at L6995.
If good, check C6991/96 and R6995.
If all good, change U6990.
Be sure all traces and solders are OK.
 
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