14-Inch MacBook Pro Water Damage No Power Repair

This 14-inch MacBook Pro A2918 came in after water damage. The customer reported that the MacBook had no power.

When we tested the USB-C ports, the two ports behaved differently. One port showed no real current draw, while the other showed limited activity. This told us the fault was likely on the logic board, not just the charger or cable.

Quick Repair Summary

Device: 14-inch MacBook Pro
Model: A2918
Logic board: 820-02757
Fault: Water damage, no power
Initial USB-C readings: one port 5V / 0.0A, one port 5V / 0.3A
Diagnosis: USB-C power-control circuit damage
Faulty chips: UF400 and UF500
Repair: Both faulty chips replaced
Result: MacBook working again

What We Found

The MacBook was not receiving power correctly through the USB-C power path.

One USB-C port stayed at 5V / 0.0A, which meant that side was not properly waking or communicating. The other port showed 5V / 0.3A, which meant there was some activity, but still not enough for the MacBook to start.

We then checked the main power line and found it was missing:

PPBUS_G3H = 0V

Further testing showed that one of the main USB-C input paths was also missing power. This led us to the first faulty chip.

First Fault Found

The first faulty chip was UF400.

After replacing UF400, both USB-C ports changed to:

5V / 0.3A

That was an improvement. It showed that the first repair restored part of the USB-C power path. However, the MacBook still did not fully start, so we continued testing.

Second Fault Found

Further testing found another missing power rail in the USB-C controller area:

PP3V3_UPC1_LDO = 0V

That rail is needed for the USB-C controller circuit to operate properly. The second faulty chip was UF500.

After replacing UF500, the MacBook powered on and worked normally again.

Why This Repair Matters

This repair is a good example of why water-damaged MacBooks should be tested carefully instead of replacing the whole logic board immediately.

The fault was not just one bad part. Water damage had affected more than one USB-C power-control chip. Replacing only the first chip improved the readings, but the MacBook still needed further diagnosis before it could fully power on.

By following the power path step by step, we found both faulty chips and repaired the original logic board.

Final Result

After replacing UF400 and UF500:

both USB-C ports responded properly;
the missing power path was restored;
the MacBook powered on;
the original logic board was repaired;
the MacBook was fully functional again.

This job is part of our collection of real Mac repair success stories, including water damage, logic board faults, screen failures and no-power problems. View more here:
Successful Mac Repair Cases

USB-C Charging Fault? We Can Help.

Need Help With a MacBook USB-C Charging Fault?

If your MacBook is stuck at 5V, keeps restarting, will not charge, or only some USB-C ports work, contact IT-Tech Online before replacing the whole logic board.

We provide professional MacBook USB-C charging repair and logic board repair in Melbourne, with mail-in service available across Australia.