| MacBook Pro A1990 Not turning on, short on PPBUS G3H repair | |
|---|---|
| Device | MacBook Pro A1990 |
| 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 A1990 MacBook Pro
Symptoms
- MacBook not turning on.
- Less than 10 Ohms on PPBUS_G3H as measured with a multimeter (short)
- Very low current draw from the charging port at 5V
Solution
Short on PPBUS_G3H
Inject 1V (increase if no reaction), watch for hot spots with thermal cam. Usually it's a bad tantalum cap
Measure PPBUS_G3H to vCORE coils (coils around CPU/GPU) IF those measure UNDER 1Ohm (0.3-0.8) then you most likely have a direct 12V short to CPU/GPU. On this board this situation is always a no fix.