820-00165 air 2017

[lincev]

Hello, it seems like a week of problems with macbook air. Equipment without liquid damage, no history any problems, never repair.

Green led and then orange. With the logic board disassembly, the same but the fan does not move. CPU DEAD?

some voltages:

PPDCIN_G3H 16.5 V
PP3V42_G3H 3.4 V
PPBUS_G3H 8.6 V
PP3V3_S5 0 V
PP5V_S4RS3 0 V
PP3V3_SUS 0 V
PP1V2_S3 0 V
PP1V8_S3 0V
PP1V05_S0 0V
PPVCC_S0_CPU 0V
ALL_SYS_PWRGD 0 V

 

[2informaticos]

When you have missing 3V3_S5, don't bother searching S4, or S3 voltages.

Post SMC_ADAPTER_EN, PM_BATLOW_L, PCH_DSWVRMEN and the 4 PCH's RTC signals.
Check diode mode to ground on all big coils.

 

[lincev]

SMC_ADAPTER_EN 0v
PM_BATLOW_L 0v
PCH_DSWVRMEN 3,30v
PPVRTC_G3H 3.40v
PCH_CLK32K_RTCX1 0.38v
PCH_SRTCRST_L 3.40v
RTC_RESET_L 3.40v
PCH INTRUDER L 3.08V
PCH INTVRMEN 3,30V
PCH_DSWVRMEN 3,30V

sorry but I don't understand "check diode mode to ground on all big coils"

Im check diode mode to ground ALL_SYS_PWRGD for short but all right

 

[2informaticos]

"I don't understand "check diode mode to ground on all big coils""
Just check diode mode to ground.
You know how to do it on ALL_SYS_PWRGD, but not on coils?
FlexBV software usually gives some readings; if you don't have good board for comparison.

However, your problem shouldn't be caused by a short there.
Do you get SMC_PM_G2_EN and AVREF_SMC?

 

[lincev]

omg sorry I have only short in L7310/20 but I have my laptop that works perfect and I have the same continuity to ground

im check all Lxxxx

SMC_PM_G2_EN 3,40v
PP3V3_S5_AVREF_SMC 3,26v

 

[2informaticos]

Low value on CPU coils doesn't mean short.

Post U7501 voltages; pins 23, 22, 12, 13, 29, 21.

 

[lincev]

Hello, when I have checked the U7501 I have been able to observe corrosion on pin 23, I do not understand how it could have formed without liquid damage. I have cleaned it and it works perfect. thanks a million friend

It is the second board with this problem, the previous one was on pin 15 maybe I don't remember

thx