MacBook Pro A1990 Not turning on, short on PPBUS G3H repair

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Revision as of 19:18, 7 October 2023 by ASRepairs (talk | contribs) (Created page with "{{stub}} {{Repair Guide |Device= |Affects parts= |Needs equipment= |Type= |Difficulty= }} ==Problem description== Repair of a common short on PPBUS_G3H on an A1990 MacBook Prothumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it! ==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== === Sh...")
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MacBook Pro A1990 Not turning on, short on PPBUS G3H repair
Device
Affects part(s)
Needs equipment
Difficulty
Type


Problem description

Repair of a common short on PPBUS_G3H on an A1990 MacBook Pro

Example image (Figure 1) -- No image yet. Help expand this page by uploading it!

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.

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