Please shoot my MacBook Air (M1) HDMI troubles?

[echolalia]

I decided to fire up REW after installing some acoustic panels and this time, I am having a hard time getting my MacBook Air to provide a signal to my AV receiver (ca. 2011 Anthem MRX 300, 1080p only).

I have tried many different HDMI cables and two different USB-C adapters (both support 4k @ 60Khz, one I use daily for computer display), but this is as far as I can get:

• MacBook can recognizes the receiver
  • MRX 300 appears in Audio Midi Setup (8 channels, 24-bit)
  • MRX 300 appears in Displays and is virtually there as an extended display (my mouse can move there)
• BUT…
  • Receiver reports no video or audio signal
  • LG OLED C1 TV flashes a green screen every few seconds OR if I switch the receivers output to "through" it says no signal.

I would normally say it's the dongles but it worked in January.

I confirmed that my Apple TV still works.

I did a factory reset on the receiver, still no dice.

Would love any guidance as I'm stumped and want to get REW working!

 

[sam_adams]

I decided to fire up REW after installing some acoustic panels and this time, I am having a hard time getting my MacBook Air to provide a signal to my AV receiver (ca. 2011 Anthem MRX 300, 1080p only).

I have tried many different HDMI cables and two different USB-C adapters (both support 4k @ 60Khz, one I use daily for computer display), but this is as far as I can get:

• MacBook can recognizes the receiver
  • MRX 300 appears in Audio Midi Setup (8 channels, 24-bit)
  • MRX 300 appears in Displays and is virtually there as an extended display (my mouse can move there)
• BUT…
  • Receiver reports no video or audio signal
  • LG OLED C1 TV flashes a green screen every few seconds OR if I switch the receivers output to "through" it says no signal.

I would normally say it's the dongles but it worked in January.
I confirmed that my Apple TV still works.
I did a factory reset on the receiver, still no dice.
Would love any guidance as I'm stumped and want to get REW working!

This sounds like an HDMI handshake issue.

Obvious questions:

Have you tried another HDMI port on the receiver?

Have you tried direct in to any of the ports on the TV?

Have you tried mirroring instead of extending the display?

Have you tried a different connection sequence, i.e.; disconnect, shutdown, reconnect, power on external devices, start Mac?

Are you using ARC(Audio Return Channel)/CEC from the TV to the receiver?

Have you tried the shortest cable that you have?

Adapters can be flakey sometimes even if they worked an hour ago.

The Apple USB-C Digital AV Multiport Adapter A2119 should work but it can be finicky sometimes displaying the exact symptoms you describe.

This Lenovo adapter works on Macs with full audio video support.

These StarTech adapters work with full audio video support at both 4K/30 and 4K/60.

 

[echolalia]

These are all fantastic questions! Much appreciated!

This sounds like an HDMI handshake issue.

Have you tried another HDMI port on the receiver?

I did try two but I could try the third and final one. The Apple TV 4K connects without issue (actually, it was pixellated looking at first but in Apple TV settings I think I selected 1080p/60 and it was fine.

Have you tried direct in to any of the ports on the TV?

Yes and that worked though REW was not able to send discrete channels of audio (on first attempt). Should the toslink pass-through work? If so that's the easiest route.

Have you tried mirroring instead of extending the display?

Yes. No difference. From the Mac display prefs, it looks like it works. I think the receiver shows No Signal or weirder 480p. The TV just flashes green.

Have you tried a different connection sequence, i.e.; disconnect, shutdown, reconnect, power on external devices, start Mac?

Yes a bunch of different sequences, powering down/up in different orders. I wasn't terribly methodical about it.

Are you using ARC(Audio Return Channel)/CEC from the TV to the receiver?

My TV is new, but my receiver is too old to support it.

Have you tried the shortest cable that you have?

From the receiver to the TV yes (and it's an 8k cable) but not from the computer.

Adapters can be flakey sometimes even if they worked an hour ago.

I love the MacBook Air but two USB-C ports mean you enter the dongleverse world of hell. Terrible product category to navigate.

The Apple USB-C Digital AV Multiport Adapter A2119 should work but it can be finicky sometimes displaying the exact symptoms you describe.

I used to have one but it doesn't do 4K/60hz so I sold it.

This Lenovo adapter works on Macs with full audio video support.

These StarTech adapters work with full audio video support at both 4K/30 and 4K/60.

The dongle I used is the Satechi ST-UCMBAM / 879961009410 and I use it daily for my 4K monitor without issue.

The other I is the belkin usb-c/hdmi 4k/60hz adapter.

I have more time today to troubleshoot. Maybe it will just magically work!

Thanks for the great questions.