820-00163 - PM_SLP_SUS_L Cycling

[ronaldo]

Hi everyone.
I need help, please.

This mac came as no power after battery run out.
Opened and found a little corrosion on the board due to humidity and dust.
All cleaned, and I found C9327 0 PPVIN_S5_HS_GPU_ISNS shorted to ground, so CAP replaced, and then I found U8001 shorting PP5V_S5 to ground, U8001 replaced and short is gone.
Problem is after I plug the charger I heard a pop somewhere on the board. I've inspected visually the whole board and no burn marks.

Now I have
PPBUS_G3H - 12.57V
PP3V42_G3H -3.42V
PPVRTC_G3H - 3.33V
PP5V_S5 - Cycling 2.75V to 5V

On PPDCIN_G3H_ISOL - cycling
PPDCIN_G3H_ISOL - 16.52V
PDCINVSENS_EN_L_DIV - Cycling 8V, 12V and 16.6V
PM_SLP_SUS_L - Cycling 0V to 3V

I just have no idea where else to check.

 

[2informaticos]

"On PPDCIN_G3H_ISOL - cycling
PPDCIN_G3H_ISOL - 16.52V"
Not sure what this meant; isn't the same power rail?

F7140/41 still good, for sure?
Check diode mode to ground on all big coils.
3V3_S5 pulsing?

 

[ronaldo]

PPDCIN_G3H_ISOL - 16.59V steady(I mixed up with another line on my previous post)
PP5V_S3 - 0V
PP3V3_S5 - pulsing
F7140/41 still good

Coils Measurements in diode mode:
L3095 - 0.539
L7720 - 0
L7195 - 0.338
L7520 - 0.366
L7130 - 0.458
L7430 - 0.265
L7630 - 0.122
L7870 - 0.334
L7560 - 0.146
L8710 - 0.193
L8760 - 0.215
L9410 - 0.165
L9330 - 0.049
L9360 - 0.049
L7310 - 0.027
L7320 - 0.027
L7330 - 0.027

I found corrosion and burn mark inside the J3200 (port next to the screen) on the pin that connects to pin 40 on the board. But it's not shorted. But it's missing voltage on that line.

 

[2informaticos]

Try to distinguish between voltage and diode mode checkings; STOP to post "V" for diode mode readings.

"the pin that connects to pin 40 on the board"
Why should we need to open boardview and find which pin corresponds in schematic?
YOU are the one working with the board.
We only need to check the schematic.
Please post accurate information.

Apart of L7560, no other big coil pulsing voltage?

 

[ronaldo]

PIN 40 on Thunderbolt port is related to the line PP3V3RHV_S4_TBTAPWR_F this is 0V at the moment.

L7560 - PP3V3_S5 - pulsing
L7430 - PP1V35_S3 - pulsing between 0.10V to 0.15V
L7195 - P5V1_SW - 5.51V steady
L7130 - CHGR_PHASE - 12.55V steady

All the other coils has 0V

 

[2informaticos]

"L7430 - PP1V35_S3 - pulsing between 0.10V to 0.15V"
Cannot really consider as pulsing.

You should check for pulse at L7520 first.
Check for short all outputs from page 66.
You should compare readings with good board.

 

[ronaldo]

I've missed this PP5V_S0 shorted to ground.
Basically all CPU phases mosfets, U7701, U7400 and a few more components that get PP5V_S0 is dead.
Applying 1V on PP3V3_S5 Chipset U1100 gets hot.
I guess this is beyond repair, as I don't have the right tools to replace the chipset.

Thanks for your help.