The Amazon adapter was purchased a couple weeks ago and the Kanex was purched in 2012 and has worked flawlessly up until a couple months ago. We have the Amazon mini display port to HDMI as well as the Kanex iAdapt Mini DisplayPort. We have two MacBook Air computers (info below) in our office.

I believe there is a bug somewhere with an OS update.

Select any resolution and refresh rate that your display supports.

Choose Displays from the View menu to open the preferences pane.From the Apple () menu, choose System Preferences.If the display does not come up, was previously set to an unsupported resolution, and still results in no video: Start by resetting the Mac's parameter RAM. You can reset the Mac's parameter RAM and SMC. If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).If more than one video adapter is in use (or 'daisy-chained'), troubleshoot by using only one adapter.Įxample: A mini DisplayPort to DVI adapter connected to a DVI to HDMI adapter is an unsupported configuration because there is a series of adapters in use.Try unplugging the video adapter or cable and then plug it back in.Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.Thunderbolt ports and displays: Frequently asked questions (FAQ).Apple Mini DisplayPort adapters: Frequently asked questions (FAQ).About Mini DisplayPort to HDMI adapters.Refer to these articles to assist you with adapter compatibility and further configuration information: Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display.It is always good to have your notebook connected to AC power when an external display is in use. If you're using an Apple notebook, confirm the AC power cable or adapter is securely connected to the computer and the cable providing power to the display is also secure.When using an external display be sure to check the following: No video or no signal, image distortion, 'snow,' or flickering

To start troubleshooting this issue where your TV is showing No Signal with your MacBook Air plugged in, please follow the troubleshooting steps below. Thanks for using Apple Support Communities.

Mini displayport a hdmi apple