Conventional Fixtures Blew a Lamp Last night (is this what usually happens?)

[Frank]

Halfway through Act I Scene I - Bang - it sounded like a pistol shot. A S4 Jr. Zoom with about 3 hours on it blew the lamp (HPL). The actors (to their credit) barely flinched and we were able to recover by bringing in another instrument. This is the first time something like this has happened for me - do they always expire so dramatically? Might this be typical life if a bit of contamination got on the lamp surface? I'm trying to figure out if it was contaminated or defective.

Thanks for any opinions or advice,

Frank

 

[MNicolai]

Not always will they be that dramatic, but that type of explosive failure will tend to happen from time to time.

Because the lamp failed only three hours in, I would put my money on someone having touched it with their bare fingers.

The really enjoyable part for you will be taking the Jr. apart to remove all of the bits of quartz from the lamp housing. Otherwise the quartz will slowly fall out of openings in the fixture and small pieces will cause your shutters to jam up. You may also need to wipe down the reflector with a 50/50 mix of isopropyl alcohol and water -- there's a good chance the exploded lamp left a nice greenish-yellowish residue all over your reflector.

It's in your best interest to download a copy of the assembly guide because the Jr. is not the easiest fixture to get back together; there are four springs for the shutter assembly that are incredibly difficult to hold in place while you simultaneously seat the reflector and screw the halves of the fixture back together.

 

[jglodeklights]

The only way to tell is by looking at the lamp. Based on what you've stated about it, someone probably touched the glass of the lamp when installing it. And while they aren't always so dramatic, the gunshot sound is often the case as the glass itself is popping.

Again, though, you'll need to look at it to confirm, but I think it is unlikely it was a manufacturing defect.

 

[derekleffew]

It's rare, but it happens. See http://www.controlbooth.com/forums/lighting-electrics/12040-epic-fail-why-fels-bad.html . On the other hand, most often one doesn't even notice a lamp has failed, until it won't light up, especially after a re-hang.

 

[Frank]

Thanks everyone, I'll check it out soon.