This article is from the RCA SelectaVision VideoDisc FAQ, by firstname.lastname@example.org (Tom Howe) with numerous contributions by others.
Well, the simplest solution might be to run an "RCA VideoDisc Player
Wanted" advertisement in your local newspaper or nickel ads, then put
the broken player in storage as a possible source for spare parts later
on. Fully 90% of the player failures I've seen are attributable to worn
out stylus cartridges or failed rubber belts, and many of the remaining
10% are due to broken or misaligned levers and gears. These are repairs
almost any competent VCR technician could handle, but they would rarely
have a working stylus cartridge to first eliminate that as the source of
failure. The Related Sites Page available at the URL listed in (2.1)
provides additional information on obtaining CED player repair.
Sometimes a failed stylus cartridge can be identified by visual
inspection, and it is sometimes possible to identify this problem by
loading a disc into the player and listening carefully as it attempts to
enter the play mode. If a faint repetitious clicking sound is heard,
this would indicate a worn out stylus. That sound is actually produced
by the stylus lifter mechanism lowering the stylus into the grooves,
failing to get a signal lock, lifting the stylus, then repeating the
A stylus cartridge may simply needs cleaning to become functional again.
All CED players use a stylus sweeper mechanism, which is basically a felt
pad the stylus is drawn over every time a disc is loaded into the player.
If this mechanism is broken or worn out, gunk will accumulate on the
stylus tip. I have used a very thin #0 insect mounting pin to carefully
scrap this off, and these cleanings have to be repeated periodically
unless the stylus sweeper mechanism is repaired. The RCA 300 and 400
series players have an additional stylus sweeper built right into the
pickup arm. This mechanism is activated each time the player is put in
pause, or whenever the player encounters carrier distress 3 seconds in
duration (usually due to a piece of dust caught on the stylus tip).