I have a Flight 2000 with all new boards and I recently replaced the pins in the connector housings connecting to the MPU. I have very annoying ghost hits I can't figure out where to start looking.
The problem primarily manifests itself when shooting balls up the lock mech. Sometimes the game counts down the bonus. Sometimes it tilts, with the tilt, it can sometimes advance to the next ball or simply let the ball in play drain (the ball it just kicked out in the shooter lane) and restart that ball. This makes the game unplayable.
Other ghost hits I've seen so far is the 25K/Bonus Multiplier target spontaneously register but most of the times at ball eject (not all the times). The upper left slingshot randomly fires without any action in that area suggesting there is a ghost hit (switch gaps checked).
As a test I replaced all the diodes on the switches that had diodes on the switch column (or is it row?) that had the tilt switches in them. No effect. I had a similar issue with my TZ years ago and a bad diode was the culprit. However, that problem was not intermittent like it is now, I can't consistently reproduce the problem and that is driving me mad.