The Lucky 7 incident with Janice from ~1997 made me think about stuff damaged during shows.  I'm not talking about mechanical/electronic issues and I'm not talking about regular wear-and-tear.
*  The UK Wheel of Fortune had someone damage their wheel by moving it counter-clockwise.  Video is out there.
*  The Magic Toaster twice.
*  On Win, Lose, or Draw (99% sure it was the Convy version), someone tested a marker by drawing some lines on the easel instead of on the pad of paper.  The ink marks were visible for weeks.
*  And the final episode of Rhyme and Reason, supposedly.