Film-Tech Forum ARCHIVE: New Xenon bulb failure question:

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Posted by Wolff King Morrow (Member # 2226) on 08-26-2004, 03:22 AM:

So I had a sort of scary moment when I attempted to change the 4k Xenon bulb in one of our Strong Highlight II consoles. I've done this before several times, but this was a new bulb from a batch I recently ordered. Two nights ago I replaced a 4k with my last spare from an older batch and it worked fine. As usual, I ran the motor and used the manual switch to strike the bulb and check for focus. What I saw was an initial strike followed by intense flickering. I looked through the peep-hole and saw the entire envelope was now completely fogged over with a faint flickering arc flash. I shut it down immediately and removed the bulb (after waiting several minutes). The spherical glass was "milky" white to where you cannot even see the anode and cathode.

So I put the old bulb back in and it works fine. I'd like to know if prehaps I did something wrong or maybe the new bulb was defective?

It's a 4k OSRAM XBO HS OFR 135 rated current.
Thanks for any help you could give.

Posted by Dick Vaughan (Member # 540) on 08-26-2004, 03:35 AM:

Sounds as though you have a leaker where the end seal(s) have given out and allowed the gas to escape. Take a look at the Tips section . Top of the list is a very useful guide to Xenon failures.

Posted by Wolff King Morrow (Member # 2226) on 08-26-2004, 03:56 AM:

Thanks, I've already read that before a couple of times. I was just wondering if it was anything I did wrong myself. I'm always very careful doing that job (because it scares the crap out of me every time), but you never know when it might be user-error.

Posted by Dick Vaughan (Member # 540) on 08-26-2004, 04:05 AM:

Unless you have done something radically different to previous lamp changes and you have somehow manged to put excessive lateral pressure on the lamp this time it's likely to be a manufacture problem. Send it back to Osram to check it out.

Posted by Dustin Mitchell (Member # 372) on 08-26-2004, 12:50 PM:

Call the manufacturer (or if you work for a chain, call the appropriate person in the home office), that bulb will be under warranty. Dick's assesment is probably right, leaky seal.