Arri 150 w bulb extremely difficult to install in fixture.
 

My Arri softbank IV arrived today! It is great, except for one thing...the bulbs for the 150 watt fixtures are so difficult to install that I have yet to get any light from either one! You have to push down and twist...but for the life of me, I cannot seem to get the light to lock into place. Is there a specific tool or technique involved?

Are the locking pins on the base off set? Try rotating the bulb 180 degrees in your hand and trying again. Just a thought...

Spencer.

If you unscrew and slide apart the lamp housing on an Arri 150 - and make sure you have the focus knob turned all the way to move the lamp housing to the front - you should be able to easily see the socket and the way the socket is set up to receive the pins on the lamp base.

Yeah, sometimes it takes a firm push and twist. After all, this is metal designed to handle heat, not polished to make things smooth.

Just remember to use a double layer of paper towel or something similar to grip the bulb so you make absolutely certain not to get any of the oils from your fingers on it (something that WILL cause the lamp to expand unevenly and become much more prone to heat explosion!) and you should be able to simply WATCH as you compress the spring in the base and seat and twist the lamp.

The lamps are really pretty robust and won't crush all that easily.

After you've successfully done it once, you'll understand the pressure needed and it won't be a problem in the future.

Good luck.

Hi Spencer:

I agree with you, the bulb in the instrument is particularly difficult to seat. I use a lot of Arri 150s and every time a bulb blows, I know that my hand is going to hurt from pressing that replacement bulb in. The fact that you do need a layer of paper or something between your fingers and the bulb doesn't make it any easier. I find changing them once the fixture has cooled down seems to help, they seem to be more difficult to install when the instrument is hot or warm.

Just keep on working at it, you'll get it. Bill is right, the bulbs are pretty beefy so press away. I find the straight pins in the larger Arris much easier to seat than the 150 in particular.

Dan

Candelabra base globes have the two pins that stick out of the sides, be sure that you line those up correctly, then push hard and twist. Best to wear a leather glove, or something. I find that using the file on my Leatherman, to file down the twin contacts on the bottom make this operation a lot easier. You don't want to take too much off, just enough to make twisting easier, but still keeping the globe firmly seated in the base.