Martin,
You were right. The locking mechanism was simply stuck due to a minor lack of lubrication.
The dampener was also not working due to a missing screw. Fortunately, I had a correct diameter screw available and with the help of a Dremel tool, the correct length.
A very simple repair, thanks for the help! Now the Beocord 9000 is performing as it should.
However does anyone have a source for a nut and bolt, one of two that secure the Beocord 9000 in the closed position. Someone along the way came up with a replacement nut (probably from Home Depot) that works, but makes closing the case extremely difficult… where it shouldn’t be.
Once again thank you Martin for the excellent advice.
Jeff