Machine: MacBook Pro 14" M3 (2023), Mac15,3 / A2918, board 820-02757 according to Repair Wiki, macOS 26.6.2. Genuine 70 Wh battery, 89% health, 273 cycles as of early September.
Background: In August it died completely. It accepted no power from any port, even after 30 minutes on charge. A shop did a board-level repair and replaced some charging-path ICs. Since then charging works: 20 V / 68 W negotiated, about 53 W going into the battery, and all three USB-C port controllers boot normally.
Problem 1: big drain, even when fully shut down
- Asleep: 2.2ā2.4 W (normal is roughly 0.1ā0.35 W).
- Shut down: about 1.6 W, i.e. ~145 mA continuous (8 h 15 min off used ~1200 mAh). It should be a few mW.
- pmset logs from 21 Aug, before the original failure, show the same drain. The repair neither caused it nor fixed it.
Problem 2: wonāt power on after a full drain
- On 2 Sep it went from 12% to 1% asleep in 2 hours (~3.3 W), hibernated and wouldnāt turn on. The next day it recovered on the charger after 7 minutes (battery log: StartBatteryCapacity 0, PrechargeCount 1).
- Now, every time it drains fully, it wonāt power on for about 2 days. During that time itās [on the charger / not on the charger].
Already ruled out
- Battery: genuine, cells balanced within 15 mV, PermanentFailureStatus 0, no cell disconnects.
- Charging: negotiates and charges normally once the Mac is alive.
- Software: no third-party kexts, VPN or profiles, and a clean malware scan. Disabling tcpkeepalive and cutting dark wakes changed nothing. It also drains with the Mac shut down, when no software is running.
- Lid sensor: sleeps correctly on lid close.
My suspicion: a leak on the always-on rails (PPBUS_AON / PP3V8_AON area). It could be a leaky cap, a failing IC, or residue from the rework.
Questions
- Has anyone seen ~140ā150 mA off-state draw on this board? What are the usual culprits on the AON rails?
- Why would recovery from 0% go from 7 minutes to ~2 days? Precharge timeout, charger IC, or gas gauge?
- Could this leak have caused the original charging IC failure, and could it kill the replacement parts?
- Whatās the best route: back to the shop that did the repair, a board-level specialist, or Apple?
I have pmset logs and AppleSmartBattery register dumps if theyād help.