Macbook Pro 2012 820-3115 no orange light


New member
Hi, I have a 3115 that doesnt get an orange light. Green light is present but seems to blink a little. No liquid damage after checking with Microscope.

Voltages measure as follows:
PPDCIN_G3H: Moving between 16.2 and 16.8v
PPBUS_G3H: 12.54 - 12.57
PP3V42_G3H: On U6901 Swinging from 3 - 3.42v on pin 4 stable on pin 5
PP5V_S5: 4.97
PP3V3_S5: 3.29
PP3V3_S4: 0v
PP5V_S0: 0v
SMC_Reset_L: 3.45v
U7000: pin 17/18 and pin 27/28 , 3.5ohm and 20 ohm,

Resistors R7005/7011/7010/7051/7052/7021/7022 all OK (accept R7010 measures 0 but also on a working board i guess its an error in the schematics which mentions 30.1k).



New member
Hi Duke, no no obvious liquid spill checked it with microscope, SMC area clean too. With battery connected it also stays green with a little blink


Staff member
Since you say PP5V_S0: 0v I am guessing this is dead. Since you mention PPBUS_G3H and PPDCIN_G3H jumping back and forth I imagine the charger is being shut off due to a short circuit up ahead. What is the resistance to ground on PP3V3_S0/PP5V_S3/the rest? My guess is short circuit to ground on PP5V_S3.


New member
I checked following lines and didnt find short to ground yet:

PPDCIN_G3H: 0.629
PPBUS_G3H: 0.450
PP3V42_G3H: 0.363
PP5V_S5: 0.523
PP3V3_S5: 0.157
PP3V3_S4: 0.411
PP5V_S3: 0.145
PP5V_S0: 0.423

On a working board I get

PPDCIN_G3H: 0.633
PPBUS_G3H: 0.446
PP3V42_G3H: 0.353
PP5V_S5: 0.514
PP3V3_S5: 0.132
PP3V3_S4: 0.376
PP5V_S3: 0.142
PP5V_S0: 0.489


Is PP5V_S0 pulsing. Check carefully, hard to catch the short pulses on multimeter, best to use a scope with "one time trigger" activated.