This article is from the RCA SelectaVision VideoDisc FAQ, by email@example.com (Tom Howe) with numerous contributions by others.
The status of the side indicator LED's is determined by switches inside
the player that are turned on or off by the disc spine. So someone
removed the disc from the caddy and reversed its orientation when
putting it back in. To correct this problem simply remove the disc from
the caddy (another question in this FAQ specifically tells how), turn
the disc (but not the spine) around, and put it back in. For ease of
identification, the sides of all VideoDisc spines are labeled Side 1 and