Author Topic: HDMI problem  (Read 555 times)

Tim Hall

  • Victoria is my queen
HDMI problem
« on: 27 October, 2021, 07:58:21 pm »
In my place of work we had a 55 inch tv on the wall. This is fed via an HDMI cable that snakes its way across the ceiling void rom a CCTV recorder and displays a grid of CCTV images. Workshop, stores, front door, that sort of thing.

Because reasons the 55 inch TV has been replaced with a larger TV, repurposed from elsewhere. Plug it in, no picture. Turn the CCTV recorder off and on again, no joy. Plug lap top into larger TV, nice picture of my Desktop. Connect another, smaller, monitor to the HDMI lead normally feeding the big TV and we get a picture. Plug the smaller monitor directly into the CCTV recorder and we get a picture.  So the big TV works and the CCTV recorder is providing a signal.
Yes, the big TV input (HDMI n) matches the number of the socket the cable goes in to.

What obvious thing am I missing?
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: HDMI problem
« Reply #1 on: 27 October, 2021, 08:02:26 pm »
In my place of work we had a 55 inch tv on the wall. This is fed via an HDMI cable that snakes its way across the ceiling void rom a CCTV recorder and displays a grid of CCTV images. Workshop, stores, front door, that sort of thing.

Because reasons the 55 inch TV has been replaced with a larger TV, repurposed from elsewhere. Plug it in, no picture. Turn the CCTV recorder off and on again, no joy. Plug lap top into larger TV, nice picture of my Desktop. Connect another, smaller, monitor to the HDMI lead normally feeding the big TV and we get a picture. Plug the smaller monitor directly into the CCTV recorder and we get a picture.  So the big TV works and the CCTV recorder is providing a signal.
Yes, the big TV input (HDMI n) matches the number of the socket the cable goes in to.

What obvious thing am I missing?
Have you tried switching it off and then switching it back on again?
Am I helping?

Tim Hall

  • Victoria is my queen
Re: HDMI problem
« Reply #2 on: 27 October, 2021, 08:41:44 pm »
In my place of work we had a 55 inch tv on the wall. This is fed via an HDMI cable that snakes its way across the ceiling void rom a CCTV recorder and displays a grid of CCTV images. Workshop, stores, front door, that sort of thing.

Because reasons the 55 inch TV has been replaced with a larger TV, repurposed from elsewhere. Plug it in, no picture. Turn the CCTV recorder off and on again, no joy. Plug lap top into larger TV, nice picture of my Desktop. Connect another, smaller, monitor to the HDMI lead normally feeding the big TV and we get a picture. Plug the smaller monitor directly into the CCTV recorder and we get a picture.  So the big TV works and the CCTV recorder is providing a signal.
Yes, the big TV input (HDMI n) matches the number of the socket the cable goes in to.

What obvious thing am I missing?
Have you tried switching it off and then switching it back on again?
Am I helping?
Yes.
Not ever so much...
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

redshift

  • High Priestess of wires
    • redshift home
Re: HDMI problem
« Reply #3 on: 27 October, 2021, 08:54:48 pm »
Obvious things:
Check that the output from the CCTV unit is actually compatible with the input capabilities of the new TV. Things such as frame rate, output resolution (625/50? 720p25? 1080p60?) CCTV is notorious for odd standards (anyone else found one that did 1080 PAL? Oh just me then...), and some TVs will autodetect and just show them, and some won't.

Check the input settings of the TV too. You said 'repurposed' so it may be older and not compatible with the CCTV unit. 

Back at work we had a series of monitor on stands, and some of them wanted YUV colorimetry in their HD feed, whilst others demanded RGB. Newer ones didn't care because they auto-sensed.  Symptoms were magenta and green output, but it's possible that you get no output at all if there's a resolution/colorimetry mismatch.
 
L
:)
Windcheetah No. 176
The all-round entertainer gets quite arsey,
They won't translate his lame shit into Farsi
Somehow to let it go would be more classy…

Tim Hall

  • Victoria is my queen
Re: HDMI problem
« Reply #4 on: 27 October, 2021, 09:00:08 pm »
Useful stuff, thanks. I'll dig into the specs of the CCTV and TV tomorrow.

(A bit foolish of me to think HDMI was just HDMI).
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: HDMI problem
« Reply #5 on: 28 October, 2021, 04:19:06 am »
Obligatory XKCD:- https://xkcd.com/927/
Quote from: Kim
Paging Diver300.  Diver300 to the GSM Trimphone, please...

Tim Hall

  • Victoria is my queen
Re: HDMI problem
« Reply #6 on: 29 October, 2021, 03:03:39 pm »
Fixed.  The TV (Panasonic 65EX700) didn't auto adjust resolution/accept the resolutiopn the CCTV was putting out. Fun and games with trailing HDMI leads, stolen monitors, wireless mouse and endloess rebooting and we're there.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

redshift

  • High Priestess of wires
    • redshift home
Re: HDMI problem
« Reply #7 on: 29 October, 2021, 05:34:20 pm »
Fixed.  The TV (Panasonic 65EX700) didn't auto adjust resolution/accept the resolutiopn the CCTV was putting out. Fun and games with trailing HDMI leads, stolen monitors, wireless mouse and endloess rebooting and we're there.

 :thumbsup:

30-odd years in telly, and it was always the domestic kit that was difficult!
L
:)
Windcheetah No. 176
The all-round entertainer gets quite arsey,
They won't translate his lame shit into Farsi
Somehow to let it go would be more classy…