Sankyo Dualux 1000 bulb shutoff?

[Edward Franklin]

Hello all,
I screened about 25 three-minute reels tonight on my Sankyo Dualux 1000. Everything was going fine, then I loaded another reel and suddenly the bulb wasn't working. Is there some reason besides being burnt out that it might not be working? Does it have some auto-shutoff if it gets too hot (although it never seemed to be running hot). Or maybe the film threading is off a bit? I tried 2 different reels and had the same result with both. I took the cover off and the bulb didn't feel even warm, even though it had been working just about two minutes prior.

***Edit*** After waiting a bit I took the lamp out. It doesn't appear to be burnt out, the squiggly filament is still intact and it's silver, not black.

[John Burgess]

Edward
There is no auto shut off on your projector , it's either on or off. You really need a test meter to check
the lamp , sometimes filaments look intact but in fact are not. If the filament tests good you should then check if you have a supply to the lamp holder if not you should then check the transformer for supply to lamp. If you have just shown 23 short films then the lamp has been switched on and off that many times, I would put money on a burnt filament . Hope this helps , good luck.
John

[Edward Franklin]

Ok, I'll drop by the hardware store and pick up a meter. Are the cheaper $15 multimeters easy enough to use for a novice, or should I invest in a $60 auto ranging meter?

[Tom Dennis]

EDWARD,

The 8v 50w bulb has allways been notorious for going high ressitance, i.e. bulb looks O.K. but not working. Take a real close look at filament, if you can see a minute blob on it then it has failed.But this does not allways happen.
As JOHN posted,
the best check to do is a continuity check.
If you just want to check continuity and basic voltage etc then just buy a cheap meter.
Just to check you should be getting approx 9 volts at bulb terminals.

Regards TOM

[Edward Franklin]

I may have had a bit of luck! I was going to watch something on my old Bell & Howell 10MS. It sounded like it was chewing up the leader, so I opened it up, and there I saw that it seems to have the exact same bulb -CXR/KP-GT 8v50w- as the Sankyo. I'm going to swap them out later this evening, I'll let you know what happens.

[Brian Fretwell]

Also remember that the solder on the centre of the lamp (assuming it is a P30S base0 can get worn and not make contact with the lampholder power supply spring at the base. It would still look good on a multimeter. Adding, carelfully, more solder to biuild it up could make it contact again.