MacBook Pro A1707 Not turning on, PPBUS G3H shorted to ground repair and File:Flash capacitor.jpg: Difference between pages

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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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{{stub}}
Camera Flash capacitor
{{Repair Guide
|Device=
|Affects parts=
|Needs equipment=
|Type=
|Difficulty=
}}
==Problem description==
<nowiki>#</nowiki>incomplete
[[File:Placeholder image.jpg|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 PPBUS_G3H rail.
 
[https://www.youtube.com/watch?v=33M3krGWAOU 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: <nowiki>https://www.youtube.com/watch?v=TZsvvUWUInE</nowiki> (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.

Latest revision as of 17:25, 29 October 2023

Camera Flash capacitor