MacBook Pro A1989 Not turning on, short on PPBUS G3H repair: Difference between revisions

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==Problem description==
==Problem description==
Repair of a common short on PPBUS_G3H on an A1990 MacBook Pro
Repair of a common short on PPBUS_G3H on an A1989 MacBook Pro
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
==Symptoms==
==Symptoms==

Revision as of 14:53, 14 October 2023

MacBook Pro A1989 Not turning on, short on PPBUS G3H repair
Device MacBook Pro A1989
Affects part(s) Motherboard
Needs equipment multimeter, soldering iron, soldering station, thermal camera
Difficulty ◉◉◉◌ Hard
Type Soldering, Micro-Soldering"Micro-Soldering" is not in the list (Soldering, Teardown, Part replacement, Cleaning, Software, BGA, General) of allowed values for the "Repair Guide type" property.


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Problem description

Repair of a common short on PPBUS_G3H on an A1989 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.