View source for MacBook Pro A1708 Not turning on, PPBUS G3H shorted to ground repair

{{Repair Guide
|Device=MacBook Pro A1708
|Affects parts=Motherboard
|Needs equipment=multimeter, soldering iron, soldering station, thermal camera
|Type=Soldering
|Difficulty=3. Hard
}}
{{stub}}

==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=PDKlWu1eDFA 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.