HDMI to mini display port problem

Hello spvalentine,

Thanks for using Apple Support Communities.

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

No video or no signal, image distortion, "snow," or flickering

Check connections

When using an external display be sure to check the following:

1. 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. It is always good to have your notebook connected to AC power when an external display is in use.
2. Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display. Refer to these articles to assist you with adapter compatibility and further configuration information:
   • Monitor and Display Adapter Table
   • About Mini DisplayPort to HDMI adapters
   • Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)
   • Thunderbolt ports and displays: Frequently asked questions (FAQ)
3. Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.
4. Try unplugging the video adapter or cable and then plug it back in.
5. If more than one video adapter is in use (or "daisy-chained"), troubleshoot by using only one adapter.

   Example: 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.

6. If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).

Reset the system

You can reset the Mac's parameter RAM and SMC.

Reset the resolution

Start by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:

1. Start up in Safe Mode.
2. From the Apple () menu, choose System Preferences.
3. Choose Displays from the View menu to open the preferences pane.
4. Select any resolution and refresh rate that your display supports.
5. Restart your computer.

Take care,

Alex H.

I have same problem, but its started step by step and now its very painfull. When i connecting adapter then a flash of a black screen on my laptop and a No Signal message on my television. But some times it works too, no glue why. Today I went to store to test with other TV's and everytihg works with same adapter.

I tryed safe mode, restart NVRAM - nothing better. I have both logs also, with working and not working.

I have the same issue. It started about a couple months ago.

I believe there is a bug somewhere with an OS update. We have two MacBook Air computers (info below) in our office. We have the Amazon mini display port to HDMI as well as the Kanex iAdapt Mini DisplayPort. 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.

I reset the PRAM to fix the issue. After putting the computer to sleep (lid closed) and opening, HDMI no longer works, regardless of TV or adapter.

Fully reproducible on both of our macbook Air computers. Tried with two separate TVs and different HDMI cables. (and tried a variety of variations on this).

shutting down computer or restarting does not fix. In fact after a restart and login i get the progress bar at about 5% and then the computer restarts again. (not sure if that issue is related or not)

Model Name: MacBook Air

Model Identifier: MacBookAir6,2

Processor Name: Intel Core i7

Processor Speed: 1.7 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache (per Core): 256 KB

L3 Cache: 4 MB

Memory: 8 GB

Boot ROM Version: MBA61.0099.B18

SMC Version (system): 2.13f15

Serial Number (system): [removed]

Hardware UUID: [removed]

SMC reset seemed to fix it: Resetting the System Management Controller (SMC) on your Mac - Apple Support

will keep reporting on this (as this issue seems to creep back after time)

after sleep the display no longer works (again)... one other thing to note is that the thunderbolt display works fine, the issue seems to be software/firmware when switching to HDMI.

Same issue. I really hope someone fixes this. It must have happened within the last 3 software updates because I was using a secondary monitor forever and all of a sudden it doesn't work. Just one laptop screen flicker and no signal on the monitor. Ive tried 2 adapters, 3 monitors, reset SMC, reset RAM etc.