I installed Xpin displays in to a Playboy. If you look at video below, you can hear a buzzing that is in sync with the blinking displays.
Ive replaced C23, C24, C26 and voltage regulator on solenoid board and C17 on sound board.
If I disconnect all the displays the buzzing sound goes away, hookup even one of the Xpin display and the buzzing sound comes back.If i go back to the original plasma displays - i get no buzzing sound at all.