Trouble with HDMI monitor for M1 Pro

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Level 1

4 points

Trouble with HDMI monitor for M1 Pro

I have a 14" M1 Pro (bought fall 2021). I have it connected to a Dell 4K monitor through USB-C and a LG 4K through HDMI. The Dell (USB-C connection) monitor never has issues but the LG (HDMI connection) stops being recognized by the laptop pretty regular, especially after the computer has been asleep for a bit. When I wake the computer, the Dell (USB-C connection works right away, but the LG (HDMI connection) often isn't detected. Unplugging the HDMI from the laptop and/or the monitor doesn't help, neither does turning off and turning back on the montior. The only thing that fixes it is a restart of the laptop. Which is a pretty big PITA.

Once I restart, it immediately recognizes both monitors and I am fine for a while.

Any ideas on how to fix this or what might be the issue would be appreciated!

Help, please.

MacBook Pro (2020 and later)

Posted on May 2, 2022 8:41 AM

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Answer 1

Best reply

Grant Bennet-Alder

Level 10

127,663 points

May 2, 2022 8:47 AM in response to JSSPEC

HDMI cables you want for HDMI-only Monitors (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

"4K" at 60 Hz is the TOP speed of top quality HDMI cables.

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Answer 2

JSSPEC Author

Level 1

4 points

May 2, 2022 8:50 AM in response to Grant Bennet-Alder

Ah, thanks. That's a good idea. I'm using the one that came with the LG monitor, so I assumed it would be fine... It's stamped "High Speed NEC". But I think I have a better cable or I'll buy one and try that out.

Thanks!

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Answer 3

JSSPEC Author

Level 1

4 points

May 4, 2022 2:26 PM in response to Grant Bennet-Alder

Unfortunately, that didn't do the trick.

This is the cable I got from Amazon: https://www.amazon.com/gp/product/B08X6X5FC3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1. (8k, certified ultra high speed, etc.) It works fine until it doesn't and then I need to restart, just like I originally described.

Any other ideas?

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Answer 4

May 5, 2022 10:47 AM in response to JSSPEC

That appears to show:

INPUT/OUTPUT

HDMI

Yesx2

DisplayPort

Yesx1

Headphone Out

Yes

If it will not behave itself on HDMI, you could connect it via DisplayPort. Here is an example:

Cable Matters USB-C to DisplayPort Cable - 8K Ready -- Price: $17.99

.

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Answer 5

JSSPEC Author

Level 1

4 points

May 7, 2022 9:06 PM in response to Grant Bennet-Alder

Thanks again for your help. I was using DisplayPort for my other external monitor (Dell), so I swapped it and now have the Dell connected via HDMI and the LG with DisplayPort. It's only been a couple days, but so far it's working fine. There must be something up with the HDMI port on that LG monitor (as you suspected).

Thanks!

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