I would pull the driver board and test the components. That's where all the transistors that control the lamps and flashers are.
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Solenoid.2C_Flasher.2C_and_Motor_problemsake While your at it, I would look at your HV section on the DMD board too. Mine recently when bad and cooked a few LED's.