Hi. Welcome feedback on this logic board.
820-00840
Client complained that it was not charging the battery. We originally took the logic board apart for measurements and found the logic board was working ok. Gave it back to the client and requested they bring it back for a battery replacement (charge cycles ~950 on the original battery).
Now the logic board is not booting, much like their original complaint about it being flaky.
Charger shows 20v @ 34mA / 33mA on Type C meter.
PPBUS_G3H @ 0v. No shorts. Current sense resistors into / exit on U7000 are measuring ok.
TBA_AUX_DET @ 5v1
D6905, pin #2 @ 20v5
PP3V3_G3H @ 3v42
Replaced mosfet @ Q7030 with belief it was shorted (gate & drain). However it may have been my error in measurement as the mosfet, after removal from the PCB, was fine on the resistance checks.
U7000 is a nasty WLCSP package so unable to probe all points.
Original U7000 = ISL9239HI. Sourced and replaced with ISL9239C0 from Mobile Sentrix. Was a bit reluctant to use the 'C0' for the 'HI' but many websites are listing 'C0' as a valid replacement for the A1708 logic boards.
No change after the U7000 replacement.
No voltage on L7030.
No battery is attached to the logic board.
Does this logic board require a battery to boot ?
Any ideas on why PPBUS_G3H remains OFF ?
Update #1:
Attached the now draining (fresh) battery from Mobile Sentrix. The voltage on the battery is about 11v5. This is the voltage that appears on PPBUS_G3H.
The logic board continues to consume ~34-36mA. Have fan spin upon adapter connection, chimes quickly and see the battery icon requesting to charge the battery. Then the display goes dark.
Update # 2:
Thanks to:
https://repair.wiki/w/A1708_2016,_20...ar_MacBook_Pro
Yup. That is this logic board as well. Investigating this now.
L7670 (PP5V_S4) is @ 0V.
L7690 (PP3V3_S5) is also @ 0V.
This makes sense since, both rails are being created by U7650 (TPS51980A) which takes as input, PPBUS_G3H. However, PPBUS_G3H is @ 0V.
So this cannot be the fault.
820-00840
Client complained that it was not charging the battery. We originally took the logic board apart for measurements and found the logic board was working ok. Gave it back to the client and requested they bring it back for a battery replacement (charge cycles ~950 on the original battery).
Now the logic board is not booting, much like their original complaint about it being flaky.
Charger shows 20v @ 34mA / 33mA on Type C meter.
PPBUS_G3H @ 0v. No shorts. Current sense resistors into / exit on U7000 are measuring ok.
TBA_AUX_DET @ 5v1
D6905, pin #2 @ 20v5
PP3V3_G3H @ 3v42
Replaced mosfet @ Q7030 with belief it was shorted (gate & drain). However it may have been my error in measurement as the mosfet, after removal from the PCB, was fine on the resistance checks.
U7000 is a nasty WLCSP package so unable to probe all points.
Original U7000 = ISL9239HI. Sourced and replaced with ISL9239C0 from Mobile Sentrix. Was a bit reluctant to use the 'C0' for the 'HI' but many websites are listing 'C0' as a valid replacement for the A1708 logic boards.
No change after the U7000 replacement.
No voltage on L7030.
No battery is attached to the logic board.
Does this logic board require a battery to boot ?
Any ideas on why PPBUS_G3H remains OFF ?
Update #1:
Attached the now draining (fresh) battery from Mobile Sentrix. The voltage on the battery is about 11v5. This is the voltage that appears on PPBUS_G3H.
The logic board continues to consume ~34-36mA. Have fan spin upon adapter connection, chimes quickly and see the battery icon requesting to charge the battery. Then the display goes dark.
Update # 2:
Thanks to:
https://repair.wiki/w/A1708_2016,_20...ar_MacBook_Pro
PP5V_S4 is missing but not shorted
L7670 (PP5V_S4) is @ 0V.
L7690 (PP3V3_S5) is also @ 0V.
This makes sense since, both rails are being created by U7650 (TPS51980A) which takes as input, PPBUS_G3H. However, PPBUS_G3H is @ 0V.
So this cannot be the fault.
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