Same issue with my JM. Check my thread but first check this
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Switch_Matrix_Problems
I would say it's the 2803 - or that was my problem. No visible signs of damage anywhere on the board?
https://pinside.com/pinball/forum/topic/johnny-mnemonic-williams-flippers-roll-overs