Brother motor drive KE100 not working – help please

I hope someone can point me in the right direction of what to do or try. I haven’t used my knitting machine (Brother 950i) and motor drive (KE100) for ages so I am very rusty. Thankfully the machines aren’t! and before using the 950i I cleaned, oiled and changed the sponge bar. I was trying a sample yesterday when the carriage jammed and the motor drive safety mechanism kicked in by releasing the carriage from the motor shuttle, as it should. I cleared the problem and tried to reset the motor but it will not move the shuttle. In days gone by when this happened I did not have a problem resetting the shuttle and restarting the motor. The power light is on but nothing happens when I press the foot pedal. I’ve taken the pedal apart and checked visually for loose or burnt out wires and that’s OK. I don’t know if it is the motor sensor, yarn sensor or something else. Can anyone help please?