Screen not turning on

I am getting nothing on my lcd. I just assembled and have verified connections.

Pi boots up, but no video, or Pi doesn’t even boot up?
Have you tried plugging a monitor into the Pi to see if it is sending a signal?
What model Pi and what power supply?
Power supply plugged into the Picade X board?

I teied adding a monitor and got mp dignal. I was able to get the screen to turn on using a seperate power supply. I also used another pi to the screen and got output.

It sounds like the issue is the Pi not booting up or not outputting a signal.
Try adding hdmi_force_hotplug=1 to your config.txt file.
If the Pi isn’t even booting up you’ll have to redo your SD Card with a supported OS that works on a Pi 4, assuming you are using a Pi 4.

I am ising retro pi. Is it not compatable with a pi 4 ? If not any recomendations ?

You’d have to check the Reto Pi Home page to see if they added support for the Pi 4B. I don’t game on my Pi so I can’t help you there.