**Model & History**
The device in question is a MacBook Pro 14″ from late 2024, featuring the M4 chip and is a base model. Approximately four months ago, a tea spill occurred on the keyboard. A local repair shop performed a cleaning but did not replace any parts, and the MacBook has been functioning normally since. The battery remains in good condition, and it is currently running macOS Sequoia.
**Current Symptoms**
When powering up on battery alone, the Mac operates normally until the battery runs low. The system displays a message indicating it is running on reserve battery life, followed by the yellow-triangle warning screen stating that the macOS version on the selected disk needs to be re-installed. However, if I go to Recovery and reboot the macOS, the Mac resumes normal operation. The complications arise when any external power is connected.
Regardless of whether I use an Apple 140 W charger with MagSafe 3 or a known-good 96 W USB-C brick, the MagSafe LED blinks amber for about one second before the laptop shuts off completely. This behavior occurs across both USB-C ports. Upon reconnecting the charger while the Mac is off, I briefly see a blink, but nothing happens after that. Disconnecting the charger allows me to boot once again using the remaining battery.
I have tested three different chargers and two MagSafe 3 cables while cleaning all ports with 99% isopropyl alcohol and allowing them to dry for 24 hours, but the issue persists. **What I’ve Ruled Out / Measured**
To determine the problem, I have ruled out the charger and cable as possible issues, visually inspected the MagSafe DC-in board for damage, verified that the battery fuse is intact, and noted that the liquid-detection lock does not correspond with the hard power-off incidents. **Suspicions from Research**
Based on my findings, potential causes include a faulty RAA489900/RAA489901 charger IC (U7200) or a shorted PPBUS bulk capacitor. While less likely, issues could also arise from both CD3219/3220 USB-C PD controllers or the ideal-diode MOSFET pair.
The repeated hard shut-offs may have resulted in corruption of the Signed System Volume, hence the yellow-triangle warning. **Goal**
My aim is to identify the exact issue and assess whether a U7200 re-chip or capacitor swap would be a worthwhile solution if that proves to be the root cause. I appreciate any schematics, voltage points, or any other insights you can provide. Thank you!
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