820-00850 Taking 20v, 50-70milliamps. Not turning on.


New member
Hello everyone! This is my first post here:) I am working on an 820-00850 that is taking 20v, 50-70 milliamps.

PP3V3_G3H: 3.36v
PPBUS_G3H 12.56V

The schematic I have says PPBUS rails have to be 13.1v, however on previous models of MacBook Pros, it is 12.6 that is normal. Am I correct in that PPBUS is fine or do I have a short somewhere? Also, I have tried a DFU reset and restore in Apple Configurator 2. The target Mac is recognized and enters DFU mode. However, waiting an hour or more, the host mac states that it is still installing and I get no activity out of the target mac.

Any ideas?


Staff member
First of all, welcome to the forum!

Did you try DFU from both Catalina and Big Sur?
I never heard to get stuck, you should receive an error message.

Check if all SSD voltages are present.

BTW, any history available?


New member
Thank you! Unfortunately no history is available for it. I did only try in High Sierra. Will try Catalina and Big Sur and see. Also will check if all SSD Voltages are present.


New member
Going to try the restore. However, I had also done what the repair wiki had said about shorts on the CPU VCORE coils and discovered a 2.7 ohm short. the wiki says 0.3 to 0.8 is dead CPU. Is my CPU done for?