EBD is a pain to get working 100%. All bad Plugs need repinning. Light board needs to be good. Expander light board and plugs need to be good. Any bad diodes on the playfield can cause light issues. Often times a switch on a drop target can be shorted because the center insulated tube the screw goes in is missing. I’ve spent days trying to track down all my problems. If you put game in Solenoid test mode and two fire at once you have a diode issue somewhere.