View source for MacBook Pro A2251 20V on USB-C, 0.00-0.01A current draw repair

{{Repair Guide
|Device=MacBook Pro A2251
|Affects parts=Motherboard
|Needs equipment=multimeter, soldering iron, soldering station
|Type=Soldering
|Difficulty=3. Hard
}}
{{stub}}
== Problem description ==
Dealing with a MacBook (820-01949) showing 20V on USB-C with a current draw of 0.00-0.01A.[[File:Placeholder_image.jpg|thumb|U7800 (Figure 1) -- No image yet. Help expand this page by uploading it]]
[[File:Placeholder_image.jpg|thumb|R8050 (Figure 2) -- No image yet. Help expand this page by uploading it]]

== Symptoms ==
* MacBook displaying 20V on USB-C ammeter
* Current draw registering 0.00-0.01A

== Solution ==
=== Diagnostic Steps ===
==== Check PMU (U7800) Input ====

* Verify if PMU U7800 (Figure 1) is missing 12V input (PMU_VDD_HI) caused by R8050 (Figure 2) being blown or corroded.
* Check resistance on R8050; normal value should be around '''877kΩ'''.
* Note: R8050 is part of a voltage divider circuit, so voltage will be lower on pin 2 of the resistor.

=== Repair Steps ===

==== Blown R8050 with Short to Ground ====

* If R8050 is blown and there's a short to ground on pin 2, replace both U7800 and R8050.

==== Blown R8050 without Short to Ground ====

* If R8050 is blown but no short to ground is found, replace R8050.