macbook air 2018 A1932 820-01521-A

[madjid911]

Hi,
I have a macbook air 2018 A1932 820-01521-A, with water damage on 7650, I changed U7650 U3100 AND U3200,
no start, T2 warms up slightly, but no shorts, I noticed PP3V3_G3H is low and does not release the PP1V8_G3S which feeds the bt rom
do you have any advice to help me? thank you

LOW TENSION :
PP3V3_G3H 3V22 > P1V8G3S_EN 0V > P1V8G3S_SS > 0V > PP1V8_G3S 0V
PPBUS_G3H 12V26

other voltage:
PPDCIN_G3H 5V
PP5V_G3S 5V
PPBUS_G3H 12V26
PP3V3_G3S 0V
PP1V8_G3S 0V
PP3V3_G3H_RTC 3V27
pp1V8_SLPS2R 1V79
PPVBAT_G3H_FUSE 0V20
CHGR_VBAT 0V20
PPBUS_HS_CPU 12V28
PPVIN_G3H_P5VG3S 12V28
PP5V_S5_LDO 0V
CHGR_BGATE 12V28
U3100:
PP1V1_UPC_XA_LDO_BMC C3104 0V
PP1V8_UPC_XA_LDOD C3105 1V79
PP1V8_UPC_XA_LDOA C3106 1V80
PP3V3_UPC_XA_LDO C3108 3V3
PP3V3_TBT_X_SX R2864 3V26
PP20V_USBC_XA_VBUS F3000 5V
U3200:
PP1V1_UPC_XB_LDO_BMC C3204 0V
PP1V8_UPC_XB_LDOD C3205 1V79
PP1V8_UPC_XB_LDOA C3206 1V79
PP3V3_UPC_XB_LDO C3208 3V3
PP3V3_TBT_X_SX R2864 0V 3V26
PP20V_USBC_XB_VBUS F3010 5V

[curiositymaster]

Re: macbook air 2018 A1932 820-01521-A

Have you been able to fix this issue?

[madjid911]

Re: macbook air 2018 A1932 820-01521-A

Have you been able to fix this issue?

hi
i still haven't solved the problem, the macbook is not recognized in dfu mode, can someone help me? thank you

[cruiser_]

Re: macbook air 2018 A1932 820-01521-A

I have similar readings, although my device is recognized in DFU. That low PP3V3_G3H and PPBUS_G3H are puzzling me :|

[mon2]

Re: macbook air 2018 A1932 820-01521-A

What is the value you have for PPBUS_G3H ?

If it is not a normal voltage, remove the fuse on this rail to isolate the PRODUCER (ISL buck-boost regulator) & CONSUMER (downstream / load) sides.

Then power up again and check the value of PPBUS_G3H before the fuse.

Is the value now normal ? If yes, then consumer side is a suspect. Remove all power -> meter in resistance mode -> check the resistance to ground AFTER the fuse to see if there could be a shorted cap.