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| MacBook Pro A1706 Not turning on, PPBUS G3H short repair | |
|---|---|
| Device | MacBook Pro A1706 |
| Affects part(s) | Motherboard |
| Needs equipment | multimeter, soldering iron, soldering station, thermal camera |
| Difficulty | ◉◉◉◌ Hard |
| Type | Soldering |
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Problem description
Repair of a common short on PPBUS_G3H on an A1706 MacBook Pro
Symptoms
- sub 20 ohms on PPBUS_G3H, (no power but 20V on board, which is not stuck at 5V)
- Not turning on
Solution
Inject 1 V (increase if no reaction), watch for hot spots with thermal camera. Usually it's a bad tantalum capacitor. Measure PPBUS_G3H to Vcore coils (coils around CPU/GPU). If those measure under 1 Ω (0.3–0.8Ω) then you most likely have a direct 12 V short to CPU/GPU. On this board this situation is always a no-fix.
Example video: No Power — A1706 2016 4xTBT3 TB 13" MacBook Pro 820-00239
- 0 V — PPBUS_G3HOT
- Inject 1 V into PPBUS_G3HOT rail.
- U7600 Dual MOSFET gets hot. Part number CSD58879Q3D.
- Visual inspection of shorted component shows solder ball popping out the side of component. C7601 is also damaged.
- Removed C7601, short still persists.
- Removed U7600, short gone.
- As of April 29, 2018 no donors available. Board not fixed.