Adding to the link above. I didn't read the thread thoroughly so don't know if this is covered or not but if the cleaning & regreasing etc does not work, like the motor is completely dead, there is a small resistor that you can replace. I took mine to an old school Hi-Fi bloke and he had one look, 5 mins later a new resistor was soldered in and good as new. Only charged £5.
I didn't want to replace with non OEM part because I always find fixing OEM stuff is better. Good luck!