Display not work after boot


I build my first picade with a raspberry pi 3 B+
When i want to boot the device the screen stay’s black.
The red led stay’s on on the pi and about foor 25 seconds a led is on the display board.
I have follow step by step on the building poster. Is it possible that te screen is defect or do i something wrong? Befor i build the picade my pi with retropie was fully working on tv

Try adding hdmi_force_hotplug=1 to your config.txt file.

I add this line. It worked for me!
Thanks a lot!

That good to hear, now you can have some fun. =)