ERROR = 1 indicates that the total number of steps to find the HOME filter position has exceeded 2600. The total number of steps should be less than 2000 unless the wheel is slipping. Clean the O-ring and drive shaft as described in paragraph 1. If this does not solve the problem, loosen the screws holding the motor and, while holding the motor against the filter wheel O-ring a little harder, retighten the screws.This error could also occur if the filter wheel is put in backwards. If this is done the filter wheel will not move. Make sure that the numbers and markings on the top face of the filter wheel are facing the telescope when it is inserted.
If this error condition is not corrected with the remedies described above, it may be due to the user inadvertently plugging the PC serial control cable into the RG-45 connector for the control cable going to the IFW. This sometimes bends back pins 1 and 8 of the RJ-45
connector. If pin 1 is bent back, then the ground conductor going to the Hall effect sensors will be disconnected. With a magnifier and a strong light, make sure all 8 pins are at the same level. If pins 1 and 8 are bent back slightly, use a knitting needle or small wire with a hook on the end to bend these pins back.