I have a slow close toilet seat, wood with chrome hinges. When I first
installed it a couple of years ago, a gentle push started both the seat and
lid closing with the seat closing in about 7 seconds and the lid in about
10.

Now, that same push gets the seat closing as usual, but the lid stops. I
have to manually close the lid to about 45* before it will move on it's
own. Once it starts it takes over 3 minutes to close.

This is not a big deal now but it might be if the seat begins to exhibit
the same problem.

How do these slow closing hinges work and what would make just the lid part
slow down?