MacBook Pro A1707 Not turning on, PPBUS G3H shorted to ground repair: Difference between revisions
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(Created page with "{{stub}} {{Repair Guide |Device= |Affects parts= |Needs equipment= |Type= |Difficulty= }} ==Problem description== <nowiki>#</nowiki>incomplete thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it! ==Symptoms== *sub 20 ohms on PPBUS_G3H *Not turning on ==Solution== How to find short circuits Inject 1 V (increase if no reaction), watch for hot spots with thermal cam. Usually it's a bad tantalum cap on the...") |
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==Problem description== | ==Problem description== | ||
Repair of a common short on PPBUS_G3H on an A1707 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== |
Latest revision as of 18:53, 30 October 2023
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MacBook Pro A1707 Not turning on, PPBUS G3H shorted to ground repair | |
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Device | |
Affects part(s) | |
Needs equipment | |
Difficulty | |
Type |
Problem description
Repair of a common short on PPBUS_G3H on an A1707 MacBook Pro
Symptoms
- sub 20 ohms on PPBUS_G3H
- Not turning on
Solution
Inject 1 V (increase if no reaction), watch for hot spots with thermal cam. Usually it's a bad tantalum cap on the PPBUS_G3H rail.
Example video (Taking 20 V, 0 A. Ethanol used instead of thermal cam with 0.8 V on PPBUS_G3H, resistance between PPBUS_G3H and CPU coil is 3.6 Ω) Example 2: https://www.youtube.com/watch?v=TZsvvUWUInE (Taking 20 V, 20 mA. Bad capacitor located via visual inspection)
Read the resistance from PPBUS_G3H to Vcore coils (coils around CPU/GPU) IF those measure UNDER 1 Ω (0.3–0.8) then you most likely have a direct 12 V short to CPU/GPU. On this board this situation is always a no fix.