Then click the Advanced Options tab to make sure that the file has been extracted and the system is repaired. Sometimes it won't connect at all in Clamshell and I have to leave the Mac open to get it to work at all. You must log in or register to reply here. This should reset your USB ports without restarting your computer. Since I use the El Capitan Beta (v2), my Keyboard and my mouse is disconnecting regularly (It works fine on my macbook or mini) And today, my USB-connected audiodevice Scarlet 2i2 (with 2 speakers) wont play any music. I have tried to do a reset with command + R on my MacBook Pro early 2015 because it wasn't running right anymore. This was fixed by renaming a file mobile devices…. If scanning for new hardware did not fix the problem, try restarting the computer. Indeed, USB port not working issue may also happen on Mac OS. Any way to reboot an iOS Device that is connected to a USB port via terminal (Mac terminal) and enter the appleid through command line? Ask Different is a question and answer site for power users of Apple hardware and software. Same I've been running my prior-generation 13inch Macbook Pro (2019 4 USB-C ports) in clamshell mode for over a year now without a problem, but with my new 13in MBP M1 (16GB/1TB fully patched Big Sur 11.0.1) the monitor keeps disconnecting.