A2251 - Not powering - no drop, no water

samstown

New member
Hello,

I got this A2251 from student. He said he was working on exams, he shut down the Mac and on the next morning, Mac didn't boot. He went to Apple, they said they can replace it under warranty but he would loose his data and that's not an option for him.

When pressing power button, it does nothing. USB-C charging port give different result if you plug it to right or left side. PVRAM, SMC doesn't help.

Thanks
 

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2informaticos

Administrator
Staff member
All USB-C ports must have the same behaviour.
If not, there is a problem with at least one port.
1.5A is too much for 5V input.

See if you can find schematic/boardview and start checking USB-C chips.
 

2informaticos

Administrator
Staff member
Check diode mode to ground at CC1/2 of all USB-C ports.

I was thinking that you had time to write 820-xxxxx code after 3 posts...
 

samstown

New member
so it's a 820-01949-A. No boardview available, do you have it? Can you clarify CC1/2 ?
 
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2informaticos

Administrator
Staff member
If you look at USB-C description pins and functioning, will understand the importance of these pins.
If USB meter stays black, there should be a short (or improper value) on VBUS, or CC1/2 pins.
These pins serve as hardware detection to put charger in 5V mode.
Initially, the charger doesn't send out any voltage on VBUS.

"he would loose his data and that's not an option for him."
Some people spend thousand of bucks for a laptop, no more money for an external SSD/HDD for Time Machine :(.
If the data is so importante, then MUST go for a third-party repair.
If repair fails, he has to pay for other laptop and data will be probably lost too.
Tell him don't use the new one until get money for external SSD/HDD.
Using Time Machine periodically will save him.
 

samstown

New member
Customer had a Time Machine from the day before. He lost one day, this can happened to anyone, he was working late, he saved his work and went to bed...
 

2informaticos

Administrator
Staff member
If he has Time Machine, tell him to go to Apple and replace the board in warranty.

BTW, which schematic/boardview are you using?
 

2informaticos

Administrator
Staff member
Did you really look at CD3215 chips in schematic?
Your board may have CD3217 instead, I'm not sure.

BTW, CC1/2 means CC1 AND CC2...
 
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