This video should help anyone trying to understand and troubleshoot a Bell & Howell 16mm 1500/2500 sound system. There are slight differences between models, so refer to manuals. This is an updated version of a previously uploaded video.

Chapters:
00:00 Introduction
01:34 The exciter lamp must come on!
02:47 Changing the exciter lamp
03:55 Checking the voltage at the exciter lamp
05:27 Removing the back covers from the projector to check the amplifier fuse
09:34 Remove bottom cover to inspect the amplifier
11:53 Checking for other sound system issues at the amplifier edge connector
14:26 Replacing the amplifier
20:02 Success!
20:44 Additional tests for low or garbled sound
25:52 Celebrate by viewing a sound film

Here's a link to Larry Urbanski's website: https://urbanskifilm.com/supplies.html

Here's a link to a very good 16mm film user forum: https://16mmfilmtalk.com/viewforum.ph...

Here's a link to an alphabetical list of vintage film projectors manuals: http://www.film-tech.com/warehouse/in...

Here's a link to a diagram of three common sound amplifiers used by these machines: https://web.archive.org/web/200809250...