The guider camera internal shutter is dead. The problem is internal to the guide camera housing and appears to be mechanical rather than electical. The details follow. I disconnected the 9-pin connector from the guider and made some measurements. The power supply voltages were all above the specified voltages, as one would expect from a no-load situation. The shutter voltage was 29 volts on, 0 off. Short circuit current at the camera connector was 11 amps. The resistance between pins 2 and 7 (across the solenoid coil) on the camera connector was 11.7 ohms, so it's not a shorted or open coil. These measurements eliminate any cabling problem that I can think of (shorts, opens, poor connections, etc) outside the camera. Jon -- Dr. Jon Brinkmann Apache Point Observatory Internet: brinkmann@galileo.apo.nmsu.EDU P.O. Box 59 URL: http://galileo.apo.nmsu.edu/~jb/ Sunspot, NM 88349-0059 APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 1 in the apo35-guider archive. You can find APO the archive on http://astro.princeton.edu:82/apo35-guider/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-guider@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO