Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: mr_rookes on February 12, 2017, 06:50:50 AM

Title: No hdmi output.
Post by: mr_rookes on February 12, 2017, 06:50:50 AM
I created a micro-sd with Debian Jessie for my A20-MICRO. After booting, I cannot get any output in my monitor. I connected by ssh with the unit, tried change_display.sh and got the message "Cannot find screen0_output_type variable!"
I suppose it can be a physical problem. What do you think?
Title: Re: No hdmi output.
Post by: JohnS on February 12, 2017, 04:29:12 PM
That looks to be a software problem.  Probably the sh script relies on not being run via ssh.

You _could_ also have a hardware ("physical") problem but I think you won't know till you fix the software one.

John
Title: Re: No hdmi output.
Post by: LubOlimex on February 21, 2017, 01:45:45 PM
Looking at the source code here: https://github.com/OLIMEX/OLINUXINO/blob/master/SOFTWARE/A20/A20-build-3.4.103/script_change_display_3.4.103/change_display.sh it looks like the shell script doesn't recognize any input for desired resolution. Probably the SSH input is not well-received by the board.

Title: Re: No hdmi output.
Post by: mr_rookes on February 24, 2017, 10:56:01 PM
I haven't work on it until now.
I got the change_display to work by disabling audio with a kernel arg.
But still no signal in the monitor :(
Title: Re: No hdmi output.
Post by: LubOlimex on March 08, 2017, 11:59:21 AM
Normally, you don't even need to run the config script. Official images provided by Olimex should have HDMI set as default output.

Are you using an official image? Did you test with this one: https://www.olimex.com/wiki/images/7/78/A20_OLinuxino_Micro_debian_Jessie_34_103_2G_release_12.torrent

Does your monitor have native HDMI or you use an adapter?

Best regards,
Lub/OLIMEX
Title: Re: No hdmi output.
Post by: mr_rookes on March 08, 2017, 10:43:19 PM
I am using an official image and an adapter. No native hdmi in the monitor. I tried an adapter without extra USB power and another one with extra power. None of them would provide signal to the monitor.
Title: Re: No hdmi output.
Post by: LubOlimex on March 09, 2017, 12:44:06 PM
Probably the adapter is the root of the problem. The adapters might mess with the signals - the timing and the levels are important.

Unfortunately, there isn't much else to recommend, except testing with another monitor with native HDMI. We haven't used adapters and I can't recommend any adapter.

Best regards,
Lub/OLIMEX