Fixing a Durst CLS2000 Color Head

**ic-racer** · 15-Nov-2009, 13:43

I finally picked up a CLS2000 color head. The main reason I wanted it is because I wanted better evenness of illumination, compared to a coldlight.

I was going to do a complete rebuild and restoration, but the unit I picked up was in very good shape. Thanks to the air filters on the back, the innards were pretty clean. The dichroic filters were also clean.

Before plugging it in, I inspected every connection and every circuit board. I did find that the shutter looked to be rigged 'always open' and there was a big burn mark on the shutter motor printed circuit board.

**ic-racer** · 15-Nov-2009, 13:46

After replacing the burned resistor, I checked the nearby relay and it checked out fine. I applied 24V to the input of the board and the motor spun and stopped as it should.

Those two open microswitches are pretty delicate, but it looked as if my CLS2000 head has never been split apart and tampered. This board had never been removed before.

This picture shows the new uprated 10 ohm power resistor in place.

**ic-racer** · 15-Nov-2009, 13:49

This is a view looking up toward the bulb and filters. You can see the sliding shutter is now correctly closed in between exposures.

**ic-racer** · 15-Nov-2009, 13:53

After double checking everything I plugged it all together and my first impression was that it was dead because nothing happened. After I triggered an exposure, the fans kicked in, the bulb lit and after a second delay the shutter opened. When I removed the trigger voltage, there was the correct one-second delay and then the shutter closed and the bulb turned off.

So, basically everything is working as it should!

**ic-racer** · 15-Nov-2009, 14:06

Here is some potentially useful info on the CLS2000

1) It is NOT 37 lb as the brochure says
2) It is NOT 26", mine measured at 28" (just like the CLS1800)
3) It has a lever for the auxillary Y & M filters, but it is a SINGLE reddish filter. In color printing it lets your Yellow and Magenta get farther from Cyan, but in multigrade printing it is just a neutral density filter. If I feel the need, I guess I could just replace that filter with an additional Yellow or Magenta filter to extend either of those ranges (but not possible to extend both).
4) My 'top hat' had a factory plate over the opening for the hose.
5) There indeed were TWO fans in there. One up top and one for the mixing boxes.
6) The DENSITY dial acts by narrowing the beam with two shutters.

**ic-racer** · 17-Nov-2009, 15:44

Now that the shutter is working I noticed the little brass lever on the shutter blade is very loose. It is brass and it is attached from the back like a rivet.

To tighten it up I wound silk thread very tightly around the base and under where it was loose. This tightened it up considerably. Then I added some alcohol-diluted epoxy to the thread to keep it in place.