MacbookPro A 1398---820-3332-A- PM_SLP_S4_L Missing

[Praveen Sahwal]

Hi
I have an macbook pro 820-3332-A. It has following signal present:-
PPBUS_G3H
PP3V42_G3H
PPVIN_HS_Computing_ISNS
PP18V5DCIN_ISOL
But 5V rails are not present. when i traced the problem then found that on U7201 P5VS4_EN and P5VS5_EN are not present. But PP3V3S5_EN shows 2.9V.
Then i found PM_SLP_S4_L is also missing. SMS_RESET_L and SMC_ON_OFF are present here. i also tried to have look on U1800 but could understand from where to start?
what are the steps i missing?
How can i proceed to solve this and what else i have to check please provide suggestion and guidance.
thanks

 

[2informaticos]

Do you get 3V3_S5/SUS?
Post exact PPBUS_G3H voltage.
Be sure to use original 85W charger.

 

[Praveen Sahwal]

Hi, Extremely sorry for the delayed response.
I am using an original 85W charger. and these are the reading i am getting on that machine.

PPBUS_G3H-12.32V
PP3V3_S5- 2.9V
PP3V3_SUS- 0V

 

[Praveen Sahwal]

PP5V_S0 and PP3V3_S4 are not present. I have no clue where to start.

 

[2informaticos]

Both voltages are incorrect.
Post diode mode at L7220/60 (red probe at ground).
Also post U7201 voltages; pins 23, 12, 13, 22, 29, 21.

Check voltage and diode mode at SCL/SDA lines of battery bus too.

 

[Praveen Sahwal]

Hi
Diode mode reading for L7220- .422
and L7260- .133
U7201 Pins

Pin 23- 12.30V
Pin 12-0V
Pin 13-0V
Pin 22-3.3V
Pin 29-0V
Pin 21-0V
and battery SCL- .522, SDA--.523
what should be the PPBUS_G3H in this board? it is 12.32V now.

 

[2informaticos]

12.6V is correct PPBUS_G3H; 12.5V reading is accepted too.

You are missing SMC_PM_G2_EN signal.
Do you get Magsafe light?
Is SMC_RESET_L steady high?

Any history fault available?

 

[Praveen Sahwal]

Yes, I do get Magsafe light green then goes to orange.
And SMC_RESET_L is Steady high --3.3V.
no fault history in this. no liquid split sign noticed. completely clean board.

 

[2informaticos]

Looks like SMC issue.
Check voltages and signals for U4900 (2 OF 2) block at page 41.

 

[Praveen Sahwal]

PP3V3_S5_SMC_VDDA- 3.3V
SMC_RESET_L-3.3V Steady High
PP3V3_S5_AVREF_SMC- 3.3 V
SMC_TCK-3.4V
SMC_TMS-3.4V
SMC_TDO-3.4V
SMC_TDI-3.4V
SMC_EXTAL-1.8V
SMC_XTAL-1.8V

 

[2informaticos]

Try reballing SMC first.
Change it, if SMC_PM_G2_EN still low.

 

[Praveen Sahwal]

Thanks Vali.
I tried that and it's working now. It was a bad SMC. But there is still some issues. One fan near SMC not working and Backight did work once but not after that. I think i need to reball SMC again.