MacBook Pro A1990 Question mark folder repair and MacBook Pro A2251 20V on USB-C, 0.00-0.01A current draw repair: Difference between pages
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{{Repair Guide | {{Repair Guide | ||
|Device=MacBook Pro | |Device=MacBook Pro A2251 | ||
|Affects parts=Motherboard | |Affects parts=Motherboard | ||
|Needs equipment=multimeter, soldering iron, soldering station | |Needs equipment=multimeter, soldering iron, soldering station | ||
|Type=Soldering | |Type=Soldering | ||
|Difficulty=3. Hard | |Difficulty=3. Hard | ||
}} | }} | ||
{{stub}} | {{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. | |||
Latest revision as of 15:28, 29 October 2023
| MacBook Pro A2251 20V on USB-C, 0.00-0.01A current draw repair | |
|---|---|
| Device | MacBook Pro A2251 |
| Affects part(s) | Motherboard |
| Needs equipment | multimeter, soldering iron, soldering station |
| Difficulty | ◉◉◉◌ Hard |
| Type | Soldering |
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Problem description
Dealing with a MacBook (820-01949) showing 20V on USB-C with a current draw of 0.00-0.01A.
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.