Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

[martyjelen]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

There is nothing. It looks like C7883 is burned.

[mon2]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

Remove this capacitor. Test again without this component.

[martyjelen]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

Now the U7800 is not hot anymore. Still 20V / 0.4A. Should I put the PCB back and test it again?

[mon2]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

Sure. Not sure what the true current consumption is for a working board but test it to see if you can see the display power on logo.

[martyjelen]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

It works without any problem now. Just doing a time machine backup.

Thank you very much again. Also thanks to piernov.

[mon2]

Re: Macbook A1989 - 820-00850-A Won't turn on - stuck at 5V/5mA

Excellent. This was a very good case and added to my knowledgebase.

[JulioChuts]

MacBook PRO A1989 won't turn on

Hello everyone at badcaps,

Today, I have a MacBook Pro A1989 on my workbench that is not powering on. While conducting some tests, I noticed that as soon as I connect the charger, I observed using a thermal camera that the T2 chip begins to heat up, reaching temperatures between 33 and 32 degrees Celsius. I've only measured the input voltages of 12V and 3V at the coil "L7660," but the expected 5V voltage at "L7600" is not present.

I don't have much experience with this type of equipment; my repairs are mostly focused on common laptops like HP, Samsung, etc. This is why I suspect I might be measuring incorrectly.

However, I would appreciate learning at least the basic measurements to see if I can fix this MacBook. Thank you in advance.