MDM Observatory's 8K CCD array project based at Columbia Astrophysics Laboratory: MANUAL SHUTTER RESET PROCEDURE
Arlin Crotts e-mail: (
Telephone: (212) 854-7899


CAUTION: make sure you have followed the procedures in the Basic Startup and Shutdown Procedures repeated below in blue before proceeding with the manual steps explained here.

First, disconnect the shutter power by squeezing the clip on the bottom of the white shutter power cable connector and pulling it from the small (shutter/filterwheel) power supply box. DO NOT FLIP ANY SWITCHES ON THE SHUTTER/FILTERWHEEL POWER SUPPLY. Second, disconnect the shutter control cable (25-pin) connector. Third, MAKING SURE THE TELESCOPE IS NEAR ZENITH, unscrew the two large set screws on either side of the instrument, directed into the shutter cassette. WITH THE TWO SET SCREWS LOOSENED, ONLY GRAVITY AND FRICTION ARE HOLDING THE SHUTTER CASSETTE (WITH A MASS OF ABOUT 10 kg) IN PLACE. Pull the shutter cassette out by the blue handle and set it down on a clean surface. Gently push the shutter leaves into the reset position by aligning the red marks with the edge of the shutter aperture. Re-insert the shutter cassette, pushing it up and back, firmly into place, then tighten the set screws. Insert the control cable first, then the power cable, then continue with the Basic Startup and Shutdown Procedures.

(From the Basic Startup and Shutdown Procedures page: MDM staff should connect the shutter power cable when installing the instrument. If at startup (or any other time) the shutter starts making a prolonged, chattering noise for more than about 15 seconds, unplug the shutter power (by pressing the clip on the bottom of the white, 4-pin connector with two red and black wires and pulling) and then plug it back in. If the shutter chatter still continues for more than 15 seconds, it is necessary to manually reset the shutter as described above on this page.)