I slipped off the belt from the motor pulley. Now the motor can turn without moving the carriage. I tried to turn the motor by hand (power off) and it can be turned easily. On power up the motor starts to turn for about one second and then stopps with the bell continously beeping (till power off). I observed the signals -carry-, -borrow- and -inc- with an oscilloscope. They are there when the motor turns but are the timings o.k.? Regards Axel Harten.