Halogen lamp question

[Jason Moffatt]

what else can cause these lamps to stop working if the central part that lights up has not blown and both pins are ok.

[Maurice Leakey]

Jason
Probably a defective lamp holder.
I assume you've checked the lamps on a meter set to OHMS, i.e., for impedance.


Maurice

[Jason Moffatt]

Is it possible for whatever they are filled with to escape through the white sealant around the pins if they are not properly sealed or could air maybe get in, would this stop them working.

[Nantawat Kittiwarakul]

That's the reason why I don't use NOS lamp, but newly made one instead. Had seen some old ones with corroded pin, they're badly enough for the gas inside the envelope to leak. They will work for say 5 mins before blackened out and completely burnt.

[Brian Fretwell]

I did find many years ago a lamp brand where some didn't have the filament welded properly to the pins so after a while the join there failed due to heating and cooling and the lamp failed with a good filament after 10 or so hours.

[Lee Mannering]

Can also be a fuse inside the projector and usually visible in the back :-)