Very interesting issue.
Can't be the display, as when this happens - there is also no Music. I don't believe their is a faulty component. Sounds to me like there could be a connector issue, or a cold joint somewhere on the Audio Visual board (for your machine it is a DCS sound board). As the machine "warms up" the connection is more stable.
Here's something I would try - Remove the A/V board and look behind the ceramic resistors. They are located at the top of the board - and they are vertically mounted. Reflow the resistor legs - there is one resistor that is almost always a "cold" or "dry" joint.