SMBUS_CHGR_SDA no pulse

Hello,
I have this board 820-2879 that I persisted in repairing ...

It works on battery
On charger it supplies 2.6V on PPBUS_G3H

SMBUS_CHGR_SDA do not pulse
SMBUS_CHGR_SCL pulse

I replace R5280, U7000, D6950

I think it is a faulty SMC but I want to know your opinion before putting in the trash.

I'm not familiar with how these old board work ....

Thanks in advance for your help
 

2informaticos

Administrator
Staff member
Why bad SMC, if board works on battery???

Do you get 3V42_G3H with charger alone?
Post U7000 voltages in the same case; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.
Check resistance between pins 17/18 and 27/28.
 
Thanks for your help
I think bad SMC because it does not provide the pulse of SMBUS_CHGR_SDA...

PP3V42_G3H 3,41 with charger & with battery
U7000 pin :
1 0v
2 0v
3 4,7v
9 3,8
12 3,41
13 3,41
14 2,26
15 0
17 2,6
19 5,06
20 5,06
27 20v

17/18 resistance : 2.8 ohm
27/28 resistance : 20.1 ohm

Thanks
 

2informaticos

Administrator
Staff member
"2 0v"
How do you get 5V at pins 19 & 20 then?
Check R/D7005, just in case.

"9 3,8"
Did you check resistance directly between pins 27/28???
 
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