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Macbook Pro frying USB peripherals

So this weirdest thing has happened to my Mac.


It only affects the left furthermost USB-C port. When the charger is connected to the Mac (through any of the remaining 3 ports), this one port will supply 20 volts on standby instead of the regular 5 volts, effectively frying any regular USB peripheral that's connected. When the charger is not connected, the port operates normally and supplies 5V.


The test setup is as follows: Apple USB-C to USB adapter plugged to left furthermost port, to which a regular USB cable is attached which exposes convenient measurement points for the multimeter.


Here's measurement taken of the voltage with charger disconnected:


User uploaded file


and with charger connected (to any of the remaining 3 USB-C ports):


User uploaded file

MacBook Pro TouchBar and Touch ID, macOS High Sierra (10.13.2)

Posted on Jan 3, 2018 10:47 AM

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Posted on Jan 4, 2018 9:29 AM

Hello atimbb,


I would definitely take this MacBook to an Apple Store as this problem doesn't seem to be user-fixable.

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Macbook Pro frying USB peripherals

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