put your multi meter on D.C. with the voltage on auto or at least 100V
game does not have to be started but has to be on.
if the flipper relay is energising then there must be a problem with power getting to the coils or the GND getting to the driver board.
The Flippers run off the same supply and fuse as the solenoids.
from what you said about the lamps dimming when the flipper buttons are pressed indicate a GND problem at the power supply
the inter connectors where replaced both male and female. All headers and I.C. sockets where also replaced, The interconnectors to the pins on this pair or boards are a very tight fit.
