Apple 3.5 Drive - Needs Cleaning?

[rigby@ptd.net (Jon H.)]

I picked up an "Apple 3.5 Drive" for a friend that has a GS.  After hooking
the drive to the first 3.5 drive (he had 1 3.5 drive and has 1 5.25 drive),
we turned the computer on.  We put a disk in the drive, and GS/OS (5.0)
gave some sort of disk is unreadable message.  we ejected the disk and put
it back in the same drive again and it came up OK.  

I also took the drive and tried it on a Mac.  I got the same problem - the
drive could read disks sometimes, and sometimes we would have to eject a
disk and put it back in.

Do you think this drive is broken?  Or does it need to be cleaned?  How
would I clean it?

Thank you,
Jon

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