This looks like a bad EDID read from the Pi side, which translates to an incorrect resolution sent to the TV. Looks like a problem specific to LG TVs.

Try to lock the Pi to a certain resolution with the options in config.txt and configure it to ignore the EDID sent by the TV:

hdmi_group = 1 hdmi_mode = 16 hdmi_ignore_edid = 0xa5000080

What @Ashpool suggested seems to have worked for me. In case anyone is interested, here's what I did...

First, with the RP up and running and the TV screen displaying correctly, I queried for the HDMI mode used:

$ tvservice -s state 0xa [HDMI CEA (16) RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive

From this and the RetroPie documentation on HDMI Mode I learned that in /boot/config.txt I had to set

hdmi_group=1

(for CEA) and

hdmi_mode=16

(for 1080p at 60Hz and 16:9). I also had to add

hdmi_force_hotplug=1

After rebooting the RP, the issue was resolved.

Thanks again, @Ashpool!

@mitu This help request can be closed out. I ended up uninstalling retropie and Ubuntu and put Batocera on my SSD. Batocera seems to be more user friendly in terms of initial installation and settings. From what I've read Retropie has more options/settings but my emulation needs are simple and Batocera serves me well.

@mitu thanks mitu☺️

@soulrider911 remaps are for controller configuration changes. i would change it via https://retropie.org.uk/docs/Configuration-Editor/

@Skervix Enable your tv's game mode. That's the best you can do. Run the pi4 at 1080p. I also recommend rtings.com. They measure the input lag of many tv's.

@mitu Thanks, that appears to have worked! Now the fun of getting SM64 to run smoothly.

Thanks!

@Mikeymac02 All I did in my cabinet was run the power coming in through a toggle switch first then to a outlet inside the cabinet. Then I just plugged in a good surge protector to my switched outlet to power everything. To turn on just flip the toggle switch and it boots up. To turn off, properly shutdown retropie from the menu then flip the toggle switch to kill everything else.

@duiz Here is my idea for fixing your resolution problem.

Firstly, try this.

Change this:

#disable_overscan=1

To this:
disable_overscan=1

Reset and see if that fixes it.

If that doesn't work change this :
#framebuffer_width=1280
#framebuffer_height=720

To this :
framebuffer_width=1920
framebuffer_height=1080

Make sure to remove the # before those lines.

If it doesn't work be sure to put it back the way it was.

Hopefully one of those ideas helps.

All is good. I couldn't recreate the issue. After several attempts.

@quicksilver I ended up installing a fresh image and it worked thanks for the replies or I’d still be stuck

@Guto-Du it's a possibility it's defective. Try over volting the pi (without over clocking) to see if it's more stable. If it is then your pi isn't stable at factory settings and should be sent back for replacement. I have seen multiple reports of pi zero's not stable at factory clock speeds. I think the quality control on the pi zero might be slightly less than other models. Probably because it's a $5 computer.

@malixx Good to hear you figured it out!

Hi! I'm having the same problem. Did you solved that?