A1278 820-3115-B no power

[hgoncalves]

Hi.

I have an A1278 820-3115-B with no power.

It has no green light, no fan spin, puls 0.10A from lab PSU.

Client says that some times it get an orange light in charger, and in those cases the mac powers on. Here it hasen't powered on any time.

PPBUS_G3H = 12.27V
PP3V42_G3H = 3.4V
SMC_BC_ACOK = 3.3V
SMC_BC_ACOK_VCC = 3.4V
SYS_ONEWIRE = 2.929V
PP18V5_DCIN_FUSE = 19V

PP5V_S5 = 0.029V and diode reading = 0.529
PP3V3_S5 = 0V and diode reading = 0.151
PP5V_SUS = 0V and diode reading = 0.420
PP3V3_SUS = 0V and diode reading = 0.360

No big coil seams to be shorted.

Can you help?

 

[2informaticos]

SMC_RESET_L OK?

 

[hgoncalves]

SMC_RESET_L = 3.446V

 

[2informaticos]

Check voltage and diode mode to ground on SCL/SDA lines of battery bus.

 

[hgoncalves]

Diode readings:
SCL = 0.521
SDA =0.523

Voltage:
SCL = 3.476V
SDA = 3.476V

 

[2informaticos]

If R7000 is good, then replace SMC.

 

[hgoncalves]

It was SMC.

TKS!