Arcam Alpha 9 drive motor hums?? Need help

My 4 yr old Arcam Alpha 9 drive motor has developed an audible hum. It is loud enough to be noticable during low level playback. It was an intermittant thing now it is fairly constant. I haven't talked to my dealer yet. I was wondering if there is any at home fixes possible. If I give a good knuckle rap it sometime temporarily fixes it. Thanks for any advice.
Have the same problem. It seems to be dependent upon the CD. I have an XRCD and a couple other which causes the problem each time I play them. Others are consistently noisless.