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820-3115 smc troubleshoot

J

jadao

Member
This one was water damage, no magsafe light, with two shorts : first on PP3V42_G3H (U7941) and second one was an internal short on PPVIN_S5_HS_OTHER_ISNS.

Fixed these issues and we are back with green light but ppbus_g3h was 8.22V :(

Before messing with smc, I checked smc_reset_l and it was present at 3.4V.
I checked pp5v_s5_ldo and it was pulsing because 5V3V3_REG_EN was pulsing and SMC_PM_G2_EN was pulsing...

For ultimate testing I decided to cut the power (PPVIN_S5_5VS3 8.22v) to U7200 and at my big surprise SMC_PM_G2_EN 5V3V3_REG_EN were steady at 3.4V but PPBUS_G3H is still 8.22V.

So my partial conclusion is that U7200 will need to be replaced.
My question in the meantime is : does PP5V_S5_LDO missing causes also SMC to not fully turn on? I am still suspecting an smc issue...
thanks
 
2informaticos

2informaticos

Administrator
Staff member
"was an internal short on PPVIN_S5_HS_OTHER_ISNS"
What exactly did you find there?

"I decided to cut the power (PPVIN_S5_5VS3 8.22v)"
Did you get 5V_S5 then?

Remove F7040 and test L7030 voltage.
If you get 12.5V, your problem is on the system side of PPBUS_G3H.
 
J

jadao

Member
Oh so sorry! with fuse in place it was 12.22V with F7049 removed it was same thing 12.28V I am confused with macbook air:) there seem no short on ppbus_g3h with 0.424 on diode mode. Sorry about that.

I just replaced U7200 and the board turns on an chimes! One variable less! U7200 was messing all pp5v_s5 down up to Smc_pm_g2_en.

I still measure 12.25v on ppbus_g3h, it works fine with a baterie but not charging and no orange light.
Diode mode on SDA line shows ... a full short to ground... SCL is ok at 0,499.

Finger crossed will start first with u7000, damn this board had a lot of bad chip + the burning hole most likely chinese charger not triping with water...
 
J

jadao

Member
I am lucky on this one it was U7000 ISL fully shorted on sda pin!
Diode mode on SDA is back to normal and exactly same as SCL line.
I just have to put backa new ISL6259, test the board, sensors etc.
You can consider it solved! Thanks 2informaticos?
 
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