Force HDMI OUTPUT

falcomvpm · July 25, 2021 at 11:00 PM

Hi People,

OS: Libreelec 18.9 (9.2.6)

Hardware: Old Laptop AMD -E-450 with Radeon HD Graphics

how to force boot from hdmi ?

NOTE:

If it turns on with the TV turned off, it stops recognizing the HDMI. Need a new BOOT with the TV on. Tried to reconnect the HDMI cable more than once. He doesn't recognize it.

config.txt does not exist

Some solutions for raspberry pi did not work on laptop

**Klojum** · July 25, 2021 at 11:49 PM Official Post

A few observations:

- VERY old laptop, AMD E450

- Booting with HDMI, not from HDMI

- Every laptop has a key combination to enable an external monitor. Is that getting in the way?

- If the TV is off, there can obviously be no HDMI-handshake (deciding on with resolution and framerate for example)

- If a config.txt file does not exist, then simply create one using the "nano" editor.

**mglae** · July 26, 2021 at 4:44 PM

1) You have to use Cusom EDID.

2) You may have to disable the display and to force HDMI output via kernel parameters. Use

Code

head /sys/class/drm/*/status

to identify the device names.

Then add a configuration like video=HDMI-A-1:D video=LVDS-1:d to the APPEND line of /flash/syslinux.cfg

Note 1) I recommend to use the run feature of the installation stick for testing. This allow changing of syslinux.cfg on a different machine.

Note 2) If there are issues with the AMD driver of the old LE 9.2.6 kernel try LE 9.97.1

falcomvpm · July 30, 2021 at 8:50 PM

Quote from mglae
1) You have to use Cusom EDID.
2) You may have to disable the display and to force HDMI output via kernel parameters. Use
Code
head /sys/class/drm/*/status
to identify the device names.
Then add a configuration like video=HDMI-A-1:D video=LVDS-1:d to the APPEND line of /flash/syslinux.cfg
Note 1) I recommend to use the run feature of the installation stick for testing. This allow changing of syslinux.cfg on a different machine.
Note 2) If there are issues with the AMD driver of the old LE 9.2.6 kernel try LE 9.97.1
Display More

Thanks for your idea, I'll test it and post the result here. At first I'm turning on the TV first, then turning on the notebook. sorry for the delay in replying.desculpe a demora para responder.

falcomvpm · August 10, 2021 at 8:44 PM

hello guys, problem solved using this post.

Thread

[Solved] Laptop HDMI Output to TV Issue

**EDIT**

I actually just solved the issue, I plugged the older laptop back into the TV to see what the settings said, and it turns out apparently my TV refresh rate needed to be set to 30.00, so I ran the following code

(Code, 2 lines)

And now everything works! That code just disables the laptop screen's completely and displays only on the TV. So sorry for wasting anyone's time!

**ORIGINAL POST**

I've been using LibreELEC for a while now, OpenELEC before that, and the entire time I had this old…

Protocol Zero

January 31, 2019 at 10:02 PM

Force HDMI OUTPUT

[Solved] Laptop HDMI Output to TV Issue

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