Just sharing an experience that might help others.
Since we bought our Twilight Zone pin well over a year ago I have been tinkering with the clock which has never worked. I had assumed the clock didn't have much affect on game play and score so I just kept tinkering while we enjoyed the game.
First I thought it was a bad opto on original board so I bought a replacement board but clock still failed so I began tinkering with the new board (BIG mistake) til I messed it up so I gave up for a while.
Recently, I mailed entire clock assembly to a repair shop - naturally this guy recognized that I had hosed the board and sold me another new board and clock housing and mailed it all back to me as "fixed and tested" - BUT it wasn't fixed and I kept getting "clock broken" during boot diagnostics and still getting opto failures during testing. I began tracing wiring back through connectors back through the "opto board) and on to the Driver Board digging deeper and deeper without fixing anything.
I finally inspected the clock "hands" and saw that part of the opto interrupter on the minute hand was broken off. I super glued a small piece of plastic onto the interrupter to extend its' reach and then found that the clock face was warped slightly causing the repaired opto interrupt to catch on the face edge (probably reason previous owner/operator broke off the interrupter) so I put a tee-niny drop of super glue on the face back side to remove the warp and keep it flat and Shazaaam - for the first time since we bought this game the clock works perfectly and keeps perfect local time and the game is a lot more fun to play.
Amazing that I probably could have fixed the clock a long time ago without spending a cent instead of the near $300.00 I paid for parts and repairs that I didn't need to begin with.
I guess my point in typing this long story is to remind all to never forget K.I.S.S. and that even very complicated gadgets can have problems with very simple solutions if we just remember to think "simple" before we assume a game problem must need an expensive and complicated repair.
Ho, Ho and Ho with a Merry, Merry to All!