Dude that second Sega logo splash for the classics collection after the checksum screen; is that how Tee Lopes came up with Sonic Mania’s start screen music??
Clean or replace connections on wire harness or board. Also replace all capacitors in circuit, they go bad after 10 years. I had this pin it was my first pinball machine I owned. It's all time classic.
It's just the regular Sega CD startup. Sega should have done something special but this was at a time when most consoles did nothing at startup without a game present. Fun Fact: I believe the very first console with anything but a black flickering screen on startup without a game inserted was the Sega Master System Base. It had a warning message that told you to insert a game into the machine to play it. Also if you hold up and both buttons at the same time while staring at the warning screen (Buttons 1+2) you will find a secret game called Snail Maze...another first by Sega.