Cannot connect HDMI with USB-C Digital AV Multiport Adapter

I also have a similar problem.

Macbook 12 inch Retina (2015) and Apple's USB-C Digital AV Multiport Adapter. My UHD Samsung monitor flickers every few minutes. The flicker problem has been consistent:

1) tried different resolutions (1920x1080, UHD, mirror mode)

2) performed a SMC reset

3) updated the firmware of the adapter (v2.33)

4) tried various HDMI cables

I bought a third party adapter and was surprised to find that the display works without flickering (NEXT JCA374) with my Macbook 12 inch Retina. So I know it's not an issue with the Samsung UHD monitor.

I would still like to see Apple resolve this issue with the adapter or issue a replacement adapter.

(VGA exit, I use an VGA to HDMI adapter)

What is a VGA exit? The signal path direction from the MacBook is to the monitors.

Do you really mean a HDMI to VGA adapter?

They should work. If you live near an Apple store, take the adapter in to verify that it's functioning properly.

Verify that the TV is switched to the appropriate HDMI input.

Verify if the Acer monitor's VGA input is switchable also.

This did not the trick for me 😟. Whenever I plug in my monitor into the USB-C dongle via HDMI the screen starts flickering. It looks like, that the MacBook is continuously switching from single to dual screen and back. Only occasionally external monitor keeps displaying the screen. This is what I tried:

- Changed monitors (2x)

- Changed HDMI cable (3x)

- Changed USB-C to HDMI dongle (2x) - I ordered 2 for office and home.

- Restarted / Shutdown

- Power unit reset

- Re-plug of the USB-C dongle into MacBook

I'm getting the feeling, that the MacBook itself is broken.

Ideas anyone?

What they had you do is a SMC reset. Those are the key commands for it.

More properly phrased, "On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time."

Reference: https://support.apple.com/en-us/HT201295

Ideas anyone?

Your problem may be HDCP, (High-bandwidth Digital Content Protection).

Apple's Mac lines includes a form of digital copy protection that will prevent protected media, such as DRM-infused iTunes movies, from playing back on devices that aren't compliant with the new priority protection measures.

The Hollywood demanded technology is called High-bandwidth Digital Content Protection (HDCP) and aims to prevent copying of digital audio and video content as it travels across a variety of display connectors, even if such copying is not in violation of fair use laws.

Your display may not be on the "approved" list, or was removed from it. (Some displays fail the HDCP handshake more than others.)

Can you try a different display to test?

Never heard of that HDCP. I tested different displays:

- LG 27" (1920x1080) -> flickers/broken with HDMI. Works with D-SUB

- LG 24" -> flickers

- BenQ -> works via HDMI

Is there a general incompatibility between Apple and LG displays?

Note: I did a 1,5 hour session with Apple support. We also tried the SMC Reset without success.

It seems that Apple has a general Incompatibility with LG displays.

I now have to use D-SUB connector OR but an (expensive) Apple display, I guess.

....OR but an (expensive) Apple display, I guess.

Actually, Apple's only display is a Thunderbolt display, and it only works with Macs that have a Thunderbolt port.

hi there,

I have the same problem, but after that I have tried your solution, unfortunately did not work for me. Any further suggestion?

hey ISA1337,

I have the same problem, I wonder if did you finally arrived to a solution to this annoying problem?

thanks in advance

I tried a similar setup:

Macbook 2015/2016 -> USB-C Multiport Adapter with HDMI -> HDMI to VGA adapter -> VGA monitor

and it's very unstable, I don't think converting the signal twice can be stable anyway.

You may find the USB-C adapter with VGA on the market instead.