Philips DVD940 - Manual (Page 36)

Cleaning discs
Some problems occur because the disc inside the player
is dirty.To avoid these problems clean your discs regularly, in the
following way:
● When a disc becomes dirty, clean it with a cleaning cloth.Wipe the disc
from the center out.
Caution: Do not use solvents such as benzine, thinner,
commercially available cleaners, or anti-static spray intended
for analog discs.
36 BEFORE REQUESTING SERVICE