[Minolta] Mirror Slap

For grins, I purchased a Minolta Maxxum 9000 off ebay last week.  It was sold 
as is and "not working, for parts only " the item description went on to say 
the seller didn't know if the camera worked or not as they were not camera 
people and had no way to power it up, blah, blah, blah.  I shelled out all of 
$11.50 (including shipping) to find out.  Everything seems to work, it starts 
up, it meters, it focuses the lens, and when I release the shutter the mirror 
slaps back down like nobody's business!  BAM!  I am just doing this for fun, 
but any ideas?  I have a Minolta 5000, from the same generation of slrs, and 
7000i from the next, and by comparison the mirror "slap" of those two cameras 
seems like the precision of work of a Swiss made watch.

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