I got an Durst AC1200 with busted analyzer/control unit, it only allows manual (timer) function. I have some plans about converting the color head to 12V/100W bulb with a new 12V fan installed, so I could throw away the very big and now almost useless control unit. It would be easy to replace the lamp and connect it + replace the original huge fan with one or two 12V fans used for PC's. However, there is a shutter in all these big CLS color heads, and when the color head is disconnected, the shutter is closed. I wonder if anyone here knows more about this shutter? There is a small electric motor operating it but does anyone know what voltage it has? Does anyone have a circuit diagram for the CLS450/500/501? And if I want to simply mechanically disengage the shutter permanently, is it easier to access it from below or from upside? So if anyone here knows these details of the construction of CLS450/500/501/AC1200 any information would be welcome!