Try this. Take out the battery first......then plug the charger into the gun so you have power. You should see the screen power up into the main menu if it's working. While the screen is on.......plug the battery in. Once the battery is plugged in with the charger also plugged in, turn the gun off. You should then see the charging logo on the screen if all is well.
I use this on my creed all the time. If the battery power drops too low the board just won't activate. Probably a firmware issue.
If it's your screen that's broken the gun should still fire without any image.
Etek 3LT grey/black f/s
Valken Proton greyish/black f/s
68 4500 PE stubby, LP output f/s
68 4500 AIR tank(no reg) f/s
Creed Battery, eyes and noid f/s