MacBook Pro A1990 "Braindead" repair and MacBook Pro A1990 Not turning on, drawing 0.11A at 20V repair: Difference between pages

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(Created page with "{{stub}} {{Repair Guide |Device= |Affects parts= |Needs equipment= |Type= |Difficulty= }} ==Problem description== A1990 MacBook not turning on and only drawing 0.11A at 20V thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it! ==Symptoms== *MacBook not turning on *current draw of 0.11A at 20V as shown by USB-C meter ==Solution== PP2V5_NAND_SSD0 can be shorted (in this case, PPBUS_G3H luckily didn't go to S...")
 
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{{Repair Guide
{{Repair Guide
|Device=MacBook Pro A1990
|Device=
|Affects parts=Motherboard
|Affects parts=
|Needs equipment=multimeter, soldering iron, soldering station, thermal camera
|Needs equipment=
|Type=Soldering, Micro-Soldering
|Type=
|Difficulty=3. Hard
|Difficulty=
}}
}}
{{stub}}
==Problem description==
==Problem description==
Any shorted subrail on A1990 machines can cause the machine to hang on POST.  
A1990 MacBook not turning on and only drawing 0.11A at 20V
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
[[File:Placeholder image.jpg|thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it!]]
==Symptoms==
==Symptoms==


*MacBook hanging on POST
*MacBook not turning on
*current draw of 0.11A at 20V as shown by USB-C meter


==Solution==
==Solution==
PP2V5_NAND_SSD0 can be shorted (in this case, PPBUS_G3H luckily didn't go to SSD)


* Thermal imaging can reveal abnormal heat caused by a shorted component.
I replaced SSD buck converter but the short was still there, found a shorted cap on the other side of the board C9088 which relieved the short on PP2V5_NAND_SSD0
* This condition is most frequently caused by a SSD subrail, such as the 2v7 SSD power line.

Revision as of 16:29, 11 October 2023

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MacBook Pro A1990 Not turning on, drawing 0.11A at 20V repair
Device
Affects part(s)
Needs equipment
Difficulty
Type



Problem description

A1990 MacBook not turning on and only drawing 0.11A at 20V

Example image (Figure 1) -- No image yet. Help expand this page by uploading it!

Symptoms

  • MacBook not turning on
  • current draw of 0.11A at 20V as shown by USB-C meter

Solution

PP2V5_NAND_SSD0 can be shorted (in this case, PPBUS_G3H luckily didn't go to SSD)

I replaced SSD buck converter but the short was still there, found a shorted cap on the other side of the board C9088 which relieved the short on PP2V5_NAND_SSD0