HDMI connection 'no signal'

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Level 1

8 points

HDMI connection 'no signal'

Hi All,

I would really appreciate some help if anyone has come up against this..

A recurring nightmare is turning up for the show and hitting 'signal not found ' when connecting my mac pro to multiple projectors..

I am using 3-4 projectors of the thunderbolt ports with 'Belkin' converts to HDMI cable

Eventually the mac recognises them but only after repeated plugging in and out..maybe 10-20 times...(sometimes never!)

Very frustrating, nerve racking and being an intermittent problem very hard to trace the cause...

Is there a more reliable converter than the 'Belkin ' out there?..different HDMI cables ? Hybrid fibre optic?...or is the problem within the mac? or in some kind of correct connection sequence that I am not doing..?

I have this problem with both my Panasonic and Canon projectors and with long and short HDMI cables....

Really stuck! advice please...

Andrew

Posted on Dec 27, 2018 2:12 AM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

140,789 points

Dec 28, 2018 8:18 AM in response to aandrewj

There is yet another issue to vex you when connecting multiple "Legacy" (i.e., non DisplayPort family) displays.

You are limited to at most TWO legacy displays unless you use ACTIVE (contain signal re-driver circuits) adapters.

If you choose to use the built-in HDMI on the Mac Pro 2013 model, that counts as ONE of your two.

To debug, limit your setup to at most TWO legacy displays, and see if each can be made to work in turn (rather that all at once). if each works, then the only remaining problem is using ACTIVE adapters.

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Answer 2

Dec 28, 2018 10:36 AM in response to aandrewj

If you debug TODAY, before you have these ACTIVE adapters in hand, and can get each display to light up by itself or with at most one other display attached, then the only thing keeping your entire setup from working as you would like is the ACTIVE adapters.

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Answer 3

aandrewj Author

Level 1

8 points

Dec 28, 2018 7:00 AM in response to Grant Bennet-Alder

Dear Grant,

Thank you for your reply, very helpful.

I think my difficulties lies with not understanding the port/bus setup on my Mac Pro (trashcan late 2013)

which I am trying to get my head around now.

I simply thought 6 slots = 6 ports = 6 possible display...wrong as I am beginning to understand.

I am so keen to get on with an idea that I rarely read instruction manuals ( also I am dyslexic which doesn't help!)

thanks again,

Andrew

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Answer 4

aandrewj Author

Level 1

8 points

Dec 28, 2018 10:10 AM in response to Grant Bennet-Alder

Dear Grant,

Thank you, more helpful advice,

Can I ask you one further thing, when you say 'remaining problem'..In what sense a problem? it sounds that if I get hold of these Active adapters they would enable me expand my options and number of displays...

Andrew

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Answer 5

aandrewj Author

Level 1

8 points

Dec 28, 2018 10:49 AM in response to Grant Bennet-Alder

Dear Grant,

Great! I see, thank you,

You really have been most helpful,

best wishes Andrew

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Answer 6

Dec 27, 2018 7:45 AM in response to aandrewj

to get a Mac display or projector to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, no data will be sent to the display.

This query is only sent at certain times:

• at startup

• at wake from sleep

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

• on invoking Option-(Detect Display) button in Displays preferences

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

Modern Displays 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 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.

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HDMI connection 'no signal'

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