I bought the cable to my MacBook Pro to a 27 "monitor to be connected. From the very beginning there was a little trouble, that the monitor when you turn on the Mac has always gone into power saving mode. Repeated rebooting it could usually be resolved. Since I own several MacBooks I tested on a second device with the same result. After about 10 days, it was no longer possible to activate the screen. I then a similar cable of other brand but this ordered more than twice the costs this. This now runs smoothly. Therefore, it seems in my cable to have been a problem here and I sent it back again.