Hi. If I connect second monitor to my laptop and work "on it" everything is ok. But if I just switch working to monitor of laptop, second monitor starts to go black often for 1-2seconds. I don't think It is HDMI port failure, and second monitor is ok, i tested it, HDMI cable is also ok. I choose extend monitor in settings. But again problem starts when I try to use my main monitor (monitor of laptop)