Norisound 310 and 322P lamp power supply issues

[Alan Paterson]

I got my old original (from 1978) Norisound 310 out of the loft during lockdown with the intent of watching a couple of films. I let it acclimatise overnight before powering it up, then gave it a whirl after checking the condition of the belts etc. I enjoyed watching my digest of 'The Jolson Story' (which had gone pink with age). At one point, I tested running it backwards, then backwards with the lamp on. The lamp went out. I replaced the lamp but to no avail. The projector runs fine but the lamp would not light up. I guessed it was maybe a fuse that had gone on a board, but could not identify one. So, feeling dejected, back in the loft it went.

I kept any eye out on EBay for a replacement projector and found a Norisound 322P, which is a nicer machine, and during clean up then testing I happened to run the film in reverse and turn the lamp on. The lamp went out. Same problem as with the 310. Tried a new lamp and it wouldn't light up. The projector runs fine, just no apparent power to the lamp. Still couldn't identify a lamp power board fuse or anything that looked blown. Could it be a problem with the switch? Who knows. I'm not a sparkie.

Has anyone with experience of Norisound projectors seen this problem and knows how to fix it?

Since having this issue, I've bought another two Norisound 310 projectors that work fine. I just don't dare run them in reverse with the lamp on.
Any help or advice gratefully received.
Kind regards
Alan

[Mark McLaughlin]

Why are you running the films in reverse anyway? 😆

[Alan Paterson]

I was testing the functionality of the projector, to see if it worked in all positions of the rotary control switch. Any suggestions on what the problem is?
Alan

[Lee Mannering]

Hello Alan. The fault will almost certainly be one of the switches that surround the main switch shaft. You'll need to replace the switch, but I would do them all along the switch shaft block. Modern switches are more reliable.

My much loved 320 switches started failing in the 80s, so eventually, I changed all the black switches. Nothing new with just about any 8mm projector today.

Norisound were a film makers projector with many optical refinements. Only other thing I did to my 320 was have the sound head repaired.
Good as new.

[Alan Paterson]

Thanks Lee, that's very helpful. I'll look into it. It's nice to have a good starting point. - Alan