Video looks scrambled on older TV. New TV works fine

trickstar321

Hey guys I recently purchased a raspberry Pi 4 model b and I'm trying to get this problem sorted.
I own a older 65inch 1080i resolution TV. When I start the PI it boots up fine. Visually on my TV there is no distortion.
I get the 5 raspberry symbols in the top left and the boot up process is visible.
The issue is when it finishes loading and the retropie screen comes on the image is scrambled all over the screen. It looks like hundreds of horizontal lines racing all over the place. I can tell the lines match the color of the logo or whatever screen is that is supposed to be displayed, just, extremely scrambled.
I thought I might have had a bad install but I tried it on my newer 1080p smart tv and it loaded completely fine no issues.
Could this be a resolution or refresh rate issue? I tried to force 1080i resolution through raspi-config but it didn't work.
Also, I'm connecting the HDMI to my TVs DVI port using a HDMI to DVI adapter. This works for my PS3 so I do not think it's the issue.
Plan to post a video but I'm at work currently.
Anyone have an idea what going on?

Thanks.

mitu

I get the 5 raspberry symbols in the top left and the boot up process is visible.

They're 4 (one for each CPU/core), unless there's a weird image mirroring that adds an extra raspberry.

Can you post your config.txt configuration file from the sd card ? What TV model/vendor is it ?

trickstar321

Ah woops, there's actually only 4. I miscounted. The tv has some overscan due to it being a rear projection TV. Model is Hitachi 65s7000. Here is a video of them problem. http://imgur.com/gallery/zwettDG

My config file is default. I have tried changing the HDMI mode to 5 for 1080i 60hz. Didn't work.

mitu

@trickstar321 said in Video looks scrambled on older TV. New TV works fine:

My config file is default. I have tried changing the HDMI mode to 5 for 1080i 60hz. Didn't work.

So the config.txt wasn't modified. It looks like the video mode switching during the DRM/KMS initialization is not correctly changing to the right resolution.

Try adding manually to config.txt the 1080i mode:

hdmi_group=1
hdmi_mode=5

and see if the video resolution works.

trickstar321

@mitu Ah sorry I mean that my config file was default except that I changed the HDMI mode to 5 kept group at 1. Made sure to remove the hashtags as well. No success still the same scrambled video. I know the resolution changes are working correctly as I easily forced 1080p for the newer smart TV upstairs. Any other ideas I'm at a loss. I have also tried 720p on the older tv as the tv is also compatible with that resolution. Still nothing.

IyonUK

@trickstar321 tried HDMI mode 20?

trickstar321

@IyonUK yeah I've tried 5,20,39 and 40

mitu

Can you try with hdmi_safe=1 in your configuration ?

smelly

I chose to bump this thread as it was prominent in search results - yes, setting hdmi_safe to 1 was quite helpful in restoring a 480p display. Thanks, mitu.

I was able to fix this issue and restore 720p by using the following settings, which are similar to what hdmi_safe would force:

hdmi_force_hotplug=1
hdmi_ignore_edid=0xa5000080
config_hdmi_boost=4
hdmi_group=1
hdmi_mode=4
disable_overscan=0
overscan_left=24
overscan_right=24
overscan_top=24
overscan_bottom=24

see: https://www.raspberrypi.com/documentation/computers/config_txt.html#hdmi_safe

saved me $150!

dankcushions

@smelly fyi setting overscan settings without overscan_scale=1 will not apply them to emulationstation - see https://retropie.org.uk/docs/Overscan/#the-console-looks-good-but-the-picture-is-off-for-emulationstationretroarchetc (and also see further up this page for other/better ways of solving overscan issues)