View source for MacBook Air A1932 Not turning on, pulling very low current at 5V or 20V repair

{{stub}}{{Repair Guide
|Device=MacBook Air A1932
|Affects parts=Motherboard
|Needs equipment=multimeter, soldering iron, soldering station, thermal camera
|Type=Soldering
|Difficulty=3. Hard
}}
==Problem description==
Diagnosing and resolving issues where a MacBook (820-01521) is pulling very little current at either 5V or 20V as indicated by a USB-C current meter with SLPS2R and AWAKE voltages/signals cycling.
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
==Symptoms==

*MacBook not turning on
*Very low current draw at either 5V or 20V
*SLPS2R and AWAKE voltages/signals cycling

==Solution==
===Diagnostic Steps===

==== Check voltage and resistance to ground on ====

===== PP5v_G3S =====
The resistance to ground on PP5v_G3S should fairly high, well within the kilo-ohms. Voltage should be around 5v. Values less than 4.9v should be considered abnormal.

===== PP3v3_G3S =====
The resistance to ground on PP3v3_G3S should fairly high, well within the kilo-ohms. Voltage should be around 3.3v. Values less than 3.215 should be considered abnormal.

===== PP1v8_G3S =====
The resistance to ground on PP1v8_G3S should fairly high, well within the kilo-ohms. Voltage should be around 1.8v. Values less than 1.70v should be considered abnormal.

===== PP3v_G3H =====
The resistance to ground on PP3v_G3H should fairly high, well within the kilo-ohms. Voltage should be around 3.0v. Values less than 2.915 should be considered abnormal.

===Repair Steps===
If no shorts were found on the listed rails above, replace U7800.

If you found a short on the listed rails above, inject 1v into the rail and perform thermal imaging. Replace the shorted component.