To use a composite LCD on your Zega Desktop Arcade will be required to solder the yellow video signal to the Raspberry Pi itself.
Solder the yellow composite LCD wire to the TV solder pad of the Raspberry Pi Zero 2
Solder the yellow composite LCD wire to the TV solder pad of the Raspberry Pi Zero
Solder the yellow composite LCD wire to the TV solder pad (PP24) of the Raspberry Pi 3.