MacBook Air A2337, 820-02016

[MarcinRdm]

Hello Everyone,

One of my customers brought me a macbook air A2337 , probably board number 820-02016 after contact with liquid . He was in another service. When I plugged it in I can see that it stays around 5.090V and amp goes up to between 0.09 and 0.14. And it is on a loop like this. I can't find the Boardview.

 

[2informaticos]

PPBUS_AON and 3V8_AON stable?

820-02016_V1.0.bvr

drive.google.com

 

[MarcinRdm]

Is not stable, jumps from 8.5v to 12.3v.
PP3V8_AON_VDDMAIN stable 3.8v

 

[2informaticos]

Remove F5200 and check if get stable voltage at C5254.

 

[MarcinRdm]

I replaced the F5200 and still jumps from 8.5v to 12.3v.

 

[2informaticos]

Who said to replace F5200???
Please, pay atention when read the posts...

 

[MarcinRdm]

Sorry, my mistake.
C5254 has a steady 12.3v.

 

[2informaticos]

Check for short on all big coils.
Compare readings with good board.

Also check if U7700 and U8100 deliver some voltages.

 

[MarcinRdm]

Unfortunately, I don't have the same motherboard.
L5800 - 22M oHM
L5820 - 7M OHM
L5840 - 7M OHM
LP800 - 2860K OHM
L5230 - 250K OHM
LC320 - 170K OHM
Should I restore the F5200 before checking the u7700 and u8100 ?

 

[2informaticos]

Of course, PPBUS_AON must be present.

BTW, use diode mode for checking on the coils.
Switch to ohm mode only for low values; usually under 0.005-0.010 readings (diode mode).

 

[MarcinRdm]

Big coils are ok.
PP3V8_AON_VDDMAIN 3.8v
PP1V5_VLDOINT_MPMU 1.5v
PP5V_BSTLQ_MPMU 5v
P3V8AON_IMEAS 0.03v
P3V3S2_PWR_EN_MPMU pulsing to 1.1v
PVDD1_PWR_EN pulsing to 1.1v
P3V8AON_LPM 0v
PMU_RESET_L pulsing to 0.6v
BUCK4_LX0 PP1V06_S2SW_DRAM pulsing to 0.6v
PP0V764_S1_SRAM pulsing to 0.6v
PP0V72_S2_VDD_LOW pulsing to 0.5v
PP1V25_S2 pulsing to 0.9v
PPVDD_PMU_LDO_PREREG pulsing to 1v

 

[2informaticos]

If 3V8_AON is stable, you should get the LDOs from U8100.

 

[MarcinRdm]

Right...
3V8_AON is stable - 3.8v
PP1V5_VLDOINT_MPMU stable 1.5v
PP3V8_AON_VDDMAIN 3.8v stable

 

[2informaticos]

Check master PMU VLDOs; page 34, bottom side; skip NC_ rails.

 

[MarcinRdm]

PP3V8_AON_VDDMAIN - 3.8v
PP1V5_VLDOINT_MPMU - 1.5v
PP1V2_S2 - pulsing to 0.8v
PP3V3_S2_UPC - pulsing to 2v
PP1V8_AON_MPMU - 1.8v
You can see that the u8100 corner is heating up.

 

[2informaticos]

Check diode mode to ground on the small coils around U7700 and U8100.
Also check if any get voltage pulse (if not shorted).

 

[MarcinRdm]

I checked all:
L8120 - diode-mode: 0.01 - pulsing to 0.5v
L8121 - diode-mode: 0.01 - pulsing to 0.5v
L8271 - diode-mode: 0.150 - pulsing to 0.5v
L8270 - diode-mode: 0.150 - pulsing to 0.5v
L82B1 - diode-mode: 0.05 - pulsing to 0.5v
L82B0 - diode-mode: 0.05 - pulsing to 0.5V
L8100 - diode-mode: 0.1 - pulsing to 0.5v
L8101 - diode-mode: 0.01 - pulsing to 0.5v
L8102 - diode-mode: 0.01 - pulsing to 0.5v
L8112 - diode-mode: 0.01 - 0v
L8111 - diode-mode: 0.01 - 0v
L8110 - diode-mode: 0.1 - 0v
L8280 - diode-mode: 0.05 - pulsing to 0.5v
L8281 - diode-mode: 0.05 - pulsing to 0.5v
L8290 - diode-mode: 0.18 - pulsing to 0.5v
L84E0 - diode-mode: 0.3 - pulsing to 0.9v
L8230 - diode-mode: 0.5 - 0V
L22A0 - diode-mode: 0.1 - pulsing to 0.5V
L7741 - diode-mode: 0.03 - pulsing to 0.8v
L7740 - diode-mode: 0.03 - pulsing to 0.8v
L7750 - diode-mode: 0.2 - pulsing to 0.5v
L77C0 - diode-mode: 0.25 - pulsing to 0.8v
L7760 - diode-mode: 0.3 - pulsing to 0.6v

 

[2informaticos]

Switch to ohm mode for 0.01 readings and compare with good board.
I don't have any here for test.

 

[MarcinRdm]

 

[2informaticos]

Can you catch voltage pulse on the big coils?
You may have problems with U7700, or U8100; should change to discard.