This part breaks on all Beocenters of the 5000 and 7000-range. The dampening grease hardens with age and the lid gets forced up and down until finally the hinge piece breaks. I may have a new original part in stock.
Todays tip; A tiny amount of contact cleaning agent sprayed down the hinge piece losens up the grease immediately, this will free the lids movement. Contact cleaner is also good for cleaning the extremely sticky grease off parts and fingers.
Martin