Update
All light sockets rechecked and replaced in backbox -still blowing bulbs (Getting low on bulbs)
Worked out when game has finished the bonus number present goes out,game over,tilt etc are showing on backglass as they should - this part i cant understand, soon as you press either flipper button the bonus light number comes up bright then blows,the flippers dont move,just the bulb lighting up & blowing - Whats the flipper button circuit got to do with the bonus light ? Should there be any voltage in the flipper circuit when game is finished.
Ah well,back to the drawing board.