820-3462 no green light no fan

[protocold]

original 60w magsafe known good adapter(tested), machine used to work but has been in storage for 2 years. No liquid damage.

PPBUS_G3H = 12.24V
PP3V42_g3H = 3.4v
PP3V3_S5 = 0V
PP5V_S5 = 0V

SMC_RESET_L = 3.37v
SMC_BC_ACOK = 3.2v



now what?

 

[2informaticos]

Check diode mode and voltage on SCL/SDA lines of battery bus.
Post U7201 basic voltages: pins 23, 22, 12, 13, 29, 21.

 

[protocold]

SMBUS_SMC_5_G3_SDA = 0486 diode / 3.4v
SMBUS_SMC_5_G3_SCL = 0.487 diode / 3.4v

U7201:
Pin 23 = 12.24v
Pin 22 = 3.3v
Pin 12 = 0v
Pin 13 = 0v
Pin 29 = 0v
Pin 21 = 0v

 

[2informaticos]

Check C4901/02/10 voltages.
Just in case, check AVREF_SMC voltage too.
You may need to change SMC.

 

[protocold]

C4901 = 3.36v
C4902 = 3.4v
C4910 = 1.2v

AVREF_SMC = 3.3v

by the way, battery was disconnected at all times, that is assumed right? Because you were asking battery bus...

 

[2informaticos]

Try another SMC...

 

[protocold]

you previously show me SMCtool, which I haven't tried yet.. but since this board also use LM4F chip.. can I use one from A1502 onto this A1425 and flash this? But SMCtool doc said it is only for 2013-2017, this A1425 is 2012.

I didn't see 820-3462 file...

 

[2informaticos]

Then get the correct SMC, from donor board.

 

[protocold]

sorry i have overlooked that while there is no obvious liquid damages but the TP around Q5490, R5033, Q5030 do have green corrosion, e.g. TP DCIN_5V_VSENSE, DCIN_VSENSE_EN, SMC_PECI_L_R etc.. also the solder joints around components in that area is somewhat rusted(under microscope)... does this change the diagnosis?

 

[2informaticos]

Incorrect I/Vsense values can impede the SMC to start power on sequence.
Test if board turns on in SMC bypass mode.

 

[protocold]

no it doesnt, no respond in SMC bypass mode.

 

[2informaticos]

Then change SMC...