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We have just replaced a 3K bulb in a Christie projector. WHen we struck it on we have dim light on the screen. Is it a defective bulb???

It could be but I would check to see if it is one of the following;

1.improper focus/alignment of the xenon bulb and or the optical bench
2.Incorrect TAP setting on the power supply
3.Open Diode in the power supply
4.Failure of one leg of 3phase power coming from the panel

If you have any questions on how to check these things feel free to email me at This e-mail address is being protected from spambots. You need JavaScript enabled to view it

I'd bet on not being alligned properly most likly.

Though you could have gotten a bad bulb with a leaky seal.

after running it, have you noticed if the bulb is turning black?

I just had one go bad with 278 hrs on it...

In addition to everything above:

If you just pulled a working bulb, I'd be less likely to suspect diodes. In any case, make sure your current draw is in the ballpark.

Is this the same brand of bulb you used before? I've seen focus vary between brands, but not usually between bulbs of the same make.

In any case, you should probably expect to realign the bulb when you change it. If you put a lot of hours on the old one, you might have adjusted for use. Then (as NSCinemas said) there's the obvious physical stuff to check... especially if you have one of those older Christies with the glass support. Was there a spacer on the cathode (reflector) end of the bulb?... Is it still there?

As for the bulb itself... if it's pulling the kind of amperage you're used to seeing, and the bulb is still clear, you're probably OK there.

[This message has been edited by rodeojack (edited February 01, 2008).]

Any update on this? I would really really like to know what the problem was and if you solved it. I know curiosity killed the cat but the curiosity is killing me!

Just my opinion and not meant to be any kind of attack on anyone just a suggestion, but I think if you come to a public forum and ask for help you should then post was the resolution was not only to cure the people who posted to help yous curiosity but also to keep a proper archive that may help other in the future!

Anyways, we would really love to know how you made out with this as we are a community that truly does care about its members