My own 1541 never actually had problems, but it was folklore on BBS's, and I saw it happen with my brother's drive. Was easy enough to service though, just loo

My own 1541 never actually had problems, but it was folklore on BBS's, and I saw it happen with my brother's drive. Was easy enough to service though, just loosen a couple screws, nudge the motor a teensy bit, run a diagnostic disk, and repeat ... many many times. They might have just been prone to misalignment anyway, but the knocking couldn't possibly have helped.