Bolex 18-5 On/Off, Reverse, Speed Selector Switch Problem

[Joe Geiger]

My Bolex Projector was in storage for a long time. Now On/Off, Speeds and Reverse work okay when selected but bulb does not light. I have traced trouble to the Selector Switch. Sometimes I can get bulb to light by continuously turning switch and pressing in but most times bulb will not light. I suspect a problem with the switch contacts for the bulb, such as a deposits/corrosion. I have tried using top rated DeoxIt D5, LPS NoFlash spray on contact cleaners but no luck as it is difficult to actually get to switch contacts even after removing switch holder from camera frame. My next step is to try unsoldering all wires to switch, that is after photo to have re-connection diagram, so that I can remove and dismantle it. However, the intricacies I see with switch construction, i.e., may springs and levers, makes me uncertain I'll can get it back together easily. Does anybody have any experience with this or know where I can get a replacement switch.
Thanks for your help, Joe

[Paul Adsett]

Problem may not be in the switch but in the contacts between the bulb holder and the bulb. Remove the bulb and clean the bulb contacts and bulb base with alcohol. Make sure alcohol has completely evaporated before swicthing on power to the lamp. If this does not solve the problem keep trying to work the switch between lamp on and lamp off positions to remove switch contact corrosion.

[Erik Snel]

i have had this issue with many projectors, i scratch the lamp contact pins with a small hobby knife, just scratch all the oxidization off of it

[Shane C. Collins]

Which 18-5 Series projector is this? The original regular 8 or the Super 8 model? On the regular 8 version there is a small metal contact under the bulb that can cause these issues. You have to scrape that contact really well, and also make sure it's making contact with the base of the bulb. Mine was causing issues where it was not making enough contact, and so my bulb was in and out. I took the bulb out and pressed up on the contact. When I put the bulb back in it rested properly on the metal contact. If it's a Super 8 variant you have to pull the two red wires off the contacts and clean them well. Also the contacts were the bulb slides in need to be cleaned well.

[Joe Geiger]

Okay, I am sure it is not the contact strip to the bulb as I have checked this out and applied all the procedures many have recommended relative to cleaning the contact. Today with a small bright beam light and mirror I was able to look into the switch plate opening and I see a loose contact which I believe is the cause of the bulb not lighting. I'll probably need to find a new switch but replacing the switch will be a tedious task due to the number of small wires involved and the restricted space.

[Shane C. Collins]

If you decide to replace the switch you could unsolder all the small wires that run to the transformer at the back of the machine. Once those wires are free it should be a matter of just pulling the switch out with the wires still attached. Then just repeat the procedure when installing a new switch.