Kodak Ektapro Slide Projector 4020 - Manual (Page 132)

The following parts should be checked for wear and, if necessary, replaced.
The optical parts, such as LENS, CONDENSER LENS and HEAT ABSORBING GLASS should be cleaned
regularly with lens cleaner.
Ultrasonic cleaning
At present, there is no information on the reactions of the individual components. We do not suggest this method.
figure 7-1
Service Manual SM2547-1
03/98 7-2 Kodak AG, Stuttgart