USB-A to USB-C (m-m) not passing power from MBP (11-2016) to external drive.

I have a MacBook Pro (Nov 2017 w/o Touch Bar) and am trying to directly connect an SSD external drive (that I use for Time Machine) installed in a Sabrent Model# EC-UASP enclosure using a M-M USB-A 3.0 to USB-C cable.


Currently, I connect the external drive using a USB-A, 3.0 cable through an Apple or Amazon Basics USB-A to USB-C adapter. The drive gets power and functions normally.


When I use the direct USB-A to USB-C cable (no adapter) the drive receives no power and, obviously, does not mount.
I have tried Belkin and Amazon Basics M-M USB-A 3.0 to USB-C cables and neither works.


I know there are issues with USB-C specs/performance relative to charging USB-C devices such as the cables allowing too much power, but this seems different issue.


Are there specific M-M USB-A 3.0 to USB-C cables that will allow power to pass from the MacBook to an external drive? All of the available cables I have seen
state that they are capable of doing what I want to do, but I am starting to wonder if blanket statements being made by vendors about capabilities that do not exist in certain M-M USB-A 3.0 to USB-C cables.


MacBook Pro

November 2016 w/o Touch Bar

MacBook Pro, macOS High Sierra (10.13.2), November 2017 w/o Touch Bar

Posted on Dec 23, 2017 12:05 PM

Reply
1 reply

Dec 28, 2017 11:37 AM in response to camionneur88

Depending on the current-rating of the charging/powering wires, charging/powering ability could vary. If the cable does not specify it is good for 0.5Amps, 3Amps, 5Amps, or some other number, you should assume it is good for 0 Amps.


This page from monoprice will allow you to compare and contrast the cables like that offered by a vendor of a very broad line of cables and adapters. Whether you choose to acquire one of those is up to you -- I am posting their site as a view of the universe of such cables:


USB-C - The All-in-One Data, Video and Power Cable

.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

USB-A to USB-C (m-m) not passing power from MBP (11-2016) to external drive.

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.