Arri 150w focus jammed....

[bapeysteez]

Hey, not sure if anyone can help me out but I just purchased a used Arri kit from a reputable local lighting store and one of the 150w fresnals happens to be jammed. It was working when I brought it home and set it up and then I happened to turn the focus knob and now it is jammed and will not turn. When I tilt the light I hear something sliding back and forth. I was just wondering if anyone has ever taken one apart or know the mechanism behind the focus where the problem would be or how to fix it. Thanks!

-Matt

 

[taormina]

Should be easy to see what's wrong. Did you open the hinged lens cover? Most of these ride on two rails operated by a cable which is attached to a knob. Open the cover and have a look.

 

[Cool Lights]

Is it a cable or a screw drive attached to the knob? What I've seen before is a set of two rails and a screw drive running down the middle. Its really unusual for one of the rails to slip out of its slot but if it did, there would be a jam for sure. You'll need to take it apart and pay particular attention about where the rails go and if anything is making it possible for the rails to get out of slot. For instance, a slight manufacturing defect where one rail is a bit shorter than the other and its just enough to last in slot for a while but can get out occasionally.

 

[filmat11]

If you find a short,off white spacer(looks like the size of the lead in a pencil )
This is placed in the track to prevent the bulb/filament from running off the end of the interior track. Remove screws in the end of light and carefully replace this spacer. For a light so little, there are several parts and screws. Make sure you make a mental note where everything goes once you disassemble it.