Environment
- MacBook Pro : Mac Sierra OS X 10.12.4 upgrade
- External Monitor : Crossover 285K UHD LED(4K)
- connected using HDMI-HDMI cable between Mac and Monitor
Problem
After Mac Sierra 10.12.4 upgrade, external monitor is not detected and is not working.
Sometimes external monitor is working as input source change in monitor.
Solution
Change cable from HDMI-HDMI to Thunderbolt-DisplayPort.
Now my external monitor is working well.
