When you are energizing the flippers, it is tripping another switch.
First, turn the game off, reseat the connectors on the driver board and the interconnect harness (connects the MPU to the driver board).
Second, check the lugs on the flipper coils to make sure the wires haven’t come disconnected (broken solder). If they are ok, check the playfield switches to make sure none of the leafs are getting inadvertent contact or arcing. Check the rubber tension on each switch too.