820-3462 No Green Light

[p99p]

I get a 820-3462 board with bad battery and some corrosion on c7517 changed the cap and clean up the area but still no green light on charger
PPBUS_G3H is pretty low with 12,3V SMC_RESET_L is present SYS_ONEWIRE is present too i reballed SMC but still no change some hints for me ?

 

[2informaticos]

Do you get 3V42_G3H?
SMC_PM_G2_EN present?

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

 

[p99p]

Sry for late response was late here so here are the messurements
PP3V42_G3Hat C6908 = 3,416V
SMC_PM_G2_EN at R7940 = 0V

I hope this are the right SCL/SDA lines:

SMBUS_SMC_5_G3_SCL = 3,416V // .508
SMBUS_SMC_5_G3_SDA = 3,415 // .509

 

[2informaticos]

Check voltage and signals for U4900 (2 OF 2) at page 39.
Also check for 12MHz oscillation at Y5010.

 

[p99p]

PP3V3_S5_SMC_VDDA at L4901	3,415
PP3V3_S5_SMC	3,3
SMC_WAKE_L	3,129
PP1V2_S5_SMC_VDDC	1,2
SMC_RESET_L	3,3
WIFI_EVENT_L	0
SMC_CLK32K	0
SMC_EXTAL	0
SMC_XTAL	0
SMC_TCK	3,4

SMC_TMS	0
SMC_TDO	0
SMC_TDI	3,4
PP3V3_S5_AVREF_SMC	3,29

Y5010 no voltage no oscillation

 

[2informaticos]

Check R5010, C5010/11 and traces; may need to replace them, as Y5010 too.
DC voltage should be 1-1.2V approx; best to check with o-scope.

 

[p99p]

R5010 Value is OK
C5010/11 no short to ground caps are looking good
I don't have a dono (does is right ? Is it called dono ?) board ATM for this is
if tried to test another crystal from a broken 820-00840 with 24Mhz I inject 1V and was taking a measurement with o-scope it was showing 24Mhz, so maybe It's possible to test this crystal the same way but don't know if SMC can handle this maybe de-solder it and try without the board.

 

[2informaticos]

12MHz crystal is available on other MacBook boards.
You can't check the caps with your eyes.
If resistor is good, then try another crystal.
If still no signal, then change the caps.