Bell & Howell 1552 sound not working

[Caleb Perhne]

I have a Bell and Howell projector I was given from my old high school a few months ago and have had to repair several things but am now stuck not sure how to fix the next problem.

I replaced the worm gear and the belt. Now, the picture runs fine but the sound isn’t working. The sound light worked and the knob made a rustling noise in the speaker when turned after the worm gear replacement but not after the belt replacement.

I replaced the sound light bulb, but still no luck. I’m assuming this is something electrical with the circuit board, but I haven’t the slightest clue how it works or where to begin. Any advice on how to fix it?

[Richard C. Patchett]

Greetings
Did the sound work before you replaced the worm gear???
Is there at least 1 in for slack at the bottom of film gate
The film should be tight around the two arms that move up and down
Could be a Dirty exciter lens is dirty or Miss aligned
Or a wire came off when replacing the worm
Or just a bad circuit board

[Caleb Perhne]

I don’t know if it worked before because the worm gear snapped the first time I used it, but the sound bulb at least came on both before and after the gear replacement, but it doesn’t now.

I assume it’s something circuit board related but don’t know anything about them. To do the belt replacement, I had to unplug the board. After that replacement, the sound bulb stopped lighting. I’ve unplugged and replugged the board twice in case I did it wrong, but to no avail.

[Richard C. Patchett]

I don't know if you have this manual http://www.film-tech.com/warehouse/manuals/BH1545.pdf
I May a used board need picture of yours. B&H made different ones
also some have a fuse inside by it self

[Martin Davey]

When you get the blub working one simple test you can do without loading up a film is to put a piece of card between the bulb and lens. Don't hold it there, but move it in and out of the beam. Ideally you should hear a 'thump' through the audio system each time. This will give a good indication that the whole chain is generally working well, although fine tuning may be required in the alignment of the optics but you should only go there if you really, really, do need to. Hopefully that part would not need any alterations.