Be sure your software on Lord Of The Rings is the latest version on the CPU board AND the Display.
There was a service bulletin where the Ring Magnet was blowing the fuse due to constant use and a software tweak toned down the useage to keep the fuse from blowing needlessly.
Service Bulletin:
http://www.sternpinball.com/upload/downloads/sb151.pdf

Not saying this is the flipper problem,but the service bulletin mentions the flipper coils heating up and getting weaker during play. This could cause transistors to blow over a long period of play.

I had a Lord Of The Rings on route that blew the magnet fuse 2 times and caused service calls. Upgrading the Eproms fixed this and I applied this fix to the other Lord Of The Rings we had on route.

Never saw this problem again. That was probably 3 years ago.

FYI the current version EPROM is now at Rev 10, further than Rev 8 mentioned in the service bulletin.
Go with the latest and greatest.
Hope this solves your problem.