help with Unidisk 5.25"

[st40q@rosie.uh.edu (Mooney, Christopher J.)]

I am having trouble with my Unidisk 5.25" drive on my Apple ][gs.
Whenever I boot the system, the drive seems to work okay until I am asked
for another disk(or to filp the disk over). Once I do this, the drive tries to 
get goping again, but sounds as if the mechanism which rotates the disk has
quit working, and then it starts that awful grinding noise. 

I have found that if I exert the exact kind of pressure on the release door, 
then it will get going right again, but ifI let go, it stops working. Also, 
sometimes if I press down on the top of the drive, it will start to work, but
of course will stop as soon as I remove the pressure.

Does anybody know what is causing this and if the solution is something I can
take care of myself?  I really don't want to mothball this computer, but it
has already cost me too much to resusitate it, and if I am forced to spend any
more money on a computer, it will be on a new COMPAQ-ack!

I would appreciate it if any responses can be sent to me via e-mail
st40q@jetson.uh.edu

thank you