Unexpectedly, without any warning symptoms, shutter behavior has became strange. It now makes something like double exposure: first movement counterclockwise, opening CCD for a short time (~0.1 sec, seems just passing over open position without stop), closing, then opening again for requested exposure time. After exposure, closing is clockwise. Besides, trigger out (pin 8 of J7) signal has vanished completely, level on pin 8 (provided according to SBIG Application Note from February 1, 2005) remains high. Can You please advice, what might be gone wrong and how to restore functionality?