My ST-i (sn# 12569) is also having shutter problems. Was working fine till last week then couldn't find any stars. Testing it out of the OAG with no power to the camera the shutter will open and close by tilting the camera. Connecting the USB the camera is recognized (Win 10 latest SBIG drivers and firmware in the ST-i), the shutter will still open and close by tilting the camera. Connect the ST-i to Maxim Dl (6.19) the shutter will cycle closed,open,closed, open and stay open, tilting the camera doesn't make a difference it stays open. Take a 2 sec image, No calibration, shutter closes and stays closed. Take a 2 sec image, simple auto-dark, the shutter opens for 2 sec (for the dark) then closes for the 2 sec exposure and remains closed. Disconnect from Maxim, the shutter stays closed (tilting has no effect). Unplug the USB and the shutter will open and close by tilting the camera. I can connect my ST-i c (#510230) and the shutter behaves normal. Help ! ??? Paul
