Mac Studio won’t recognize Samsung smart TV after HDMI cable extension

Question

Level 1

4 points

Mac Studio won’t recognize Samsung smart TV after HDMI cable extension

I can’t figure out how to get my Mac Studio to connect to my Samsung Smart TV. I have a couple hundred feet of HDMI fiber optic cable running between them, with a 2.1 rated HDMI-HDMI connector near one end. The connection was fine until I moved the TV to another wall and had to add another 50’ fiber optic HDMI to the cable run (hence the need for the connector). The feed worked perfectly before; now the Mac and the TV don’t recognise each other. If I plug the end of the HDMI into a Samsung computer monitor, it works just fine, so I know I’m still getting feed. I know that new 50’ strand is compatible with the TV because I’ve plugged an Apple TV in where the connector now is, and the TV recognized it. Yes, I’ve tested the other HDMI ports. I’m at my wits end, and the professional tech who installed the original setup hasn’t been able to fix it yet.

I don’t know if this is the place to ask about this because it’s probably not a specifically Apple related issue, but I need to start somewhere.

FYI, this is not a personal setup; it is for my church. Thanks in advance.

[Re-Titled by Moderator]

Mac Studio (2023)

Posted on Jan 3, 2025 06:51 AM

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Answer 1

Jan 3, 2025 01:10 PM in response to Alwaysbooks

HDMI 2.1 is a completely different protocol, electrically, than everything called HDMI that came before it.

if you don't need higher than 4K at 30 Hz, fall back to HDMI 2.0 and live happily ever after.

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Answer 2

Jan 3, 2025 01:10 PM in response to Alwaysbooks

To get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• hold the Option key while you click on the (Detect Display) button that will appear in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

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Answer 3

Alwaysbooks Author

Level 1

4 points

Jan 3, 2025 02:36 PM in response to Grant Bennet-Alder

Thank you, Grant. I will try that.

I was using 2.0 connectors before, and I thought that might the problem, so I replaced them with 2.1 connectors. I assume my smart TV and Mac Studio are both rated for 2.1 since I purchased them new within the last year or so. I'd like to get 4K60 if possible. If not, 30hz is probably fine.

FYI, I have also tried connecting my computer monitor and TV to the Mac via dongles, because sometimes Macs will only recognise second displays when they are connected via USB-C. But that has not changed anything.

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Answer 4

Jan 3, 2025 03:11 PM in response to Alwaysbooks

<< because sometimes Macs will only recognize second displays when they are connected via USB-C. >>

That is not true. Check carefully that you are allowing the Mac to recognize the display, because as I said above, no internal settings can make the picture come on.

But HDMI has been pushed so hard that it is now unrecognizable from the friendly 'everything just works with everything' over its original environment of 720i TV sets.

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Answer 5

Jan 5, 2025 07:00 AM in response to Alwaysbooks

you have at least two thought streams going here, and they are completely crossed up in my mind.

what problem are you now trying to solve?

your one computer with a nearby HDMI display, or

the gigantic two hops of fiber-optic with an adapter in between?

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Answer 6

Alwaysbooks Author

Level 1

4 points

Jan 5, 2025 09:21 AM in response to Grant Bennet-Alder

It’s both. There is a monitor right next to the Mac, but we have a second display 200’ away that we’ve connected with two long fiber optic HDMIs. That is the display that the Mac will not recognize.

The strange thing is that if I replace the TV with a computer monitor, it connects perfectly. Different display, different result.

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Answer 7

Jan 5, 2025 09:39 AM in response to Alwaysbooks

Modern Displays, including TV sets, with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.

Some displays and TVs have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.

Some displays and TVs include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own can generally not respond to the Mac's query, and will stay dark.

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