TheBackShed.com

Forum Index : Microcontroller and PC projects : How can you keep a monitor alive...

Author

Message

Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9845

Posted: 04:36am 21 Jan 2026

Copy link to clipboard

Print this post

I have a test area, with an AOC monitor, that has both VGA and HDMI connectors.
With either one, if there is no video detected after about five seconds on either port, the monitor goes to sleep, and this is a MAJOR pain in my arse.

Pretty much ALL monitors in the world, no matter what brand, do this.

Is there anything you can buy, that could perhaps sit between the monitor and the other things I want to connect to it, that will keep the monitor alive NO MATTER WHAT?

Basically, I don't want the monitor to EVER go to sleep, unless I turn the bloody thing off myself.

The constant powering off into sleep mode, is making it really difficult with some things, to see prompts and startup messages, cos the bloody monitor has gone to sleep......again.

And by the time it wakes up, you've missed messages you are trying to see.

Changing the monitor would be pointless - they ALL do this now.

I'd need something that can keep ALL types of video input alive - HDMI, VGA and DVI too, although, I don't need DVI that much, all my testing is either HDMI or VGA.

Anyone know of anything, cos this is driving me bonkers.

Edited 2026-01-22 09:07 by Grogster

Smoke makes things work. When the smoke gets out, it stops!

Plasmamac

Guru

Joined: 31/01/2019
Location: Germany
Posts: 600

Posted: 05:39am 21 Jan 2026

Copy link to clipboard

Print this post

For vga you need a fake sync signal (h or v) to keep the screen on. Vesa dpms standard
For hdmi y need a fake tmds clock shield.
You can use a pico with simple „or logic“ to create it.
Maybe you can fake a signal with the pio and a pico

Plasma

phil99

Guru

Joined: 11/02/2018
Location: Australia
Posts: 2947

Posted: 05:48am 21 Jan 2026

Copy link to clipboard

Print this post

For VGA it is usually Sync. that keeps it on. My guess is just H-sync will if you can inject pulses into that when none are arriving down the cable.

For HDMI & DVI-D only monitors, no idea but if there is a VGA input as well maybe sync pulses may keep the monitor on but don't know if it will revert to HDMI when that appears.

There may be something in the monitor's setup menu that gives HDMI priority over VGA.
Perhaps even a setting to disable "power saving mode".

I use a cheap TV as a HDMI monitor and it doesn't have a power saving mode at all.

Bryan1

Guru

Joined: 22/02/2006
Location: Australia
Posts: 1618

Posted: 06:33am 21 Jan 2026

Copy link to clipboard

Print this post

Grogs yesterday arvo I used my old Benq 19" monitor to see if I could get into the bios of these 2 optiplex 9020 computers my employer was throwing away so he gladly gave me two of them

Now as these computers have dual display ports and the monitor had hdmi found and old serial cable to use.

Now at first got nothing on the screen so I played around with the switch's on the side of the monitor and a popup came with the option of dvi or D-sub so chose D-sub and the screen came to life.

I did try on the second computer but it wouldn't boot and nothing on the screen so I'm glad one of them is OK

So maybe try those options on the monitor and see if works for you.

Regards Bryan

PeteCotton

Guru

Joined: 13/08/2020
Location: Canada
Posts: 601

Posted: 06:54am 21 Jan 2026

Copy link to clipboard

Print this post

I'm not sure if this will work for your monitor - but I've noticed that my HDMI video capture card appears to be recognised by my monitor, even when there is no signal. It is going through a HDMI switch after that - but it might worth trying.

https://www.amazon.ca/dp/B0CLNZ8267?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_32&th=1

Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 5627

Posted: 02:41pm 21 Jan 2026

Copy link to clipboard

Print this post

@Grogster,

Maybe you can buy a display panel (not a computer monitor). Most (outdoor) display panels I have seen, when there is no input signal, display diagnostics info. Day after day, until someone comes to fix it (restart the PC).

Volhout
Edited 2026-01-22 00:42 by Volhout

PicomiteVGA PETSCII ROBOTS

Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9845

Posted: 11:08pm 21 Jan 2026

Copy link to clipboard

Print this post

Thanks for all the replies - that gives me something to go on.
The forum software removed the word "Alive" on the thread title - I don't know why.
I added it back(without quotes), to make the thread title make sense again.

Smoke makes things work. When the smoke gets out, it stops!

Print this page

To reply to this topic, you need to log in.