Thank you for everyones input.

I got home from work today and played for about 15 minutes.  The hum seems to have disappeared and all coils during play and diagnostics were working.  The only thing that happened during the game was at one point the right flipper stopped work for a ball, then started working again.  Then a number of times during my playing it would double flip.  For example when I was catching or holding the ball a few times it would double flip.  Not sure if this could be related to my previous issue?

Another thing I noticed was that one of the inserts in the playfield seemed to be on permanently, although I never recall this being on all the time before, I didn't think it was a GI?  It's on the right side, the skull picture with the top hat.  See pic.  Maybe it always was and I never noticed with the old bulbs and I do now with LED's?  Does anyone else know if this is supposed to be on all the time.




Finally here is a pic of the start button on the inside.  I unscrewed the black part right down to the base but I simply cannot pull or twist out the plastic bit, it won't budge.