DIAGNOSIS The barrel or brush is not engaging with the motor drive. This is almost always because the attachment isn't clicked into place correctly, or there's debris blocking the connection.
FIX Turn the machine off. Remove the attachment. Look at the silver pin inside the attachment's socket and the corresponding hole on the Airwrap's body. Make sure both are clean and free of hair or lint. Now, firmly push the attachment onto the body until you hear and feel a distinct *click*. Don't just slide it on; it needs a positive snap. Turn it back on—the attachment should now spin.
IF THAT DIDN'T WORK Try a different attachment. If one attachment spins and another doesn't, the problem is with the non-spinning attachment's internal mechanism (likely a broken drive). If no attachments spin, the motor drive shaft in the main unit is faulty. That's a repair job.
HEADS UP Never force an attachment on or try to use it if it's not spinning. You can damage the drive pin, and that's an expensive fix.