Retropi boots with only sound then stops

[Gameboy]

I have a Raspberry Pi 3B+ and recently - after working flawlessly - screen went black. Now when I turn the console on, the screen is black and I hear retropi booting up (I hear the PlayStation logo sound but the screen stays black) then it stops and I see 4 green blinks next to the micro sd. I can’t see anything on screen but I know that retropi stops working itself because it should go into a rom and play the music when I click a button, only it doesn’t do anything at all. Help greatly appreciated! I want to buy a few more in the future, but I want to make sure this problem is fixable first!

[mitu]

@Gameboy Please add more info about your system, as described in https://retropie.org.uk/forum/topic/3/read-this-first.

You can take a look here to see how the LEDs pattern can be mapped to boot issues or hardware problems. Are you turning on the TV before starting your Pi ? Do you see the 4 raspberries and the coloured rainbow pattern at boot ?

[Gameboy]

@mitu thank you for helping, the raspberry pi is a 3B+ made to look like a gameboy so it hasn’t a screen of its own connected to the raspberry pi inside a gameboy shell. The screen is black (but there is an indication that it is on since the blackness glows when in darkness) and when I turn on the console, the introduction plays without the screen - I can hear the PlayStation intro sound that it makes - and then it stops and the 4 blinks occur. I haven’t modified the console at all and it was working perfectly for the past 4 months. It did do this thing where it would start to glitch and freeze or the console would completely shut off, but I could always just turn it back on and it would start up again. However, I was playing it and what happened was the console just fell slightly onto a pillow then the screen went black but the sound still played. Now when I turn it on, the screen stays black, the intro plays, and then it stops running. Does retropi or emulation station stop running (does it shut off) if there is no hdmi output? I’m thinking maybe the screen got bumped out of place, but it doesn’t explain why the sd card stops running or that when I click a button, the games don’t start and make noise at least.