820-3115 No charger light, PPBUS G3H is 12.25, CHanged SMC twice after reflow.

grmacs

Member
I thought the SMC would be causing the issue with the charger light not showing at all and the PPBUS_G3H not boosting. Changing twice neither have changed I think I reballed a couple of those SMC's more than once to no avail. The fact that I have PPBUS G3H at 12.25 and no charger light should imply the SMC, correct?

SMC's did come from other 3115 boards. One of the donor boards I pulled SMC from was known to boot but had other strange issue I couldn't resolve.
 

2informaticos

Administrator
Staff member
Did you check first voltage and diode mode to ground at SCL/SDA lines of battery bus???
Did you test the board alone on the desk?
 

grmacs

Member
Tested on desk.
Diode on battery bus lines is .527 and .526
3.49V with charger only at pins 4 and 6 J6950
 

2informaticos

Administrator
Staff member
Did you try another DCIN board?
Post U6900/01 voltages.
Check continuity from U6900 to central pin of Magsafe connector.
There should be a 20 ohms resistor, or just a small coil, in series.
 

grmacs

Member
YEs tried a couple different DCIN boards.
+3V at pins1,4,5 of U6900 and 1,2,4,5 of u6901
22 ohms from pin 5 U6900 to center pin of MS connector.
 

2informaticos

Administrator
Staff member
Looks like you have SMC issue.
Checl ALL signals and voltages for U4900 (2 OF 2) at page 45.
Be sure to get oscillation at Y5010.
 
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