If the drum isn’t spinning, but the motor is still running, it is most likely caused by a broken belt. Be sure to get an identical belt from the manufacturer. After removing the old belt, look for markings on the drum. Align the new belt with the marking. Wind it around the idler and motor pulleys. If the roller becomes too worn out, you need to replace it as well. You can find the roller directly underneath the tumbler. Be sure to get an original tumbler from the manufacturer and you need to unscrew the front panel. Take the worn-out tumbler out, by removing the retaining clips, then replace it with a brand-new tumbler. A more serious problem is if you have a faulty motor. You need to call a technician because replacing a motor is more complicated to do.