Thanks for the tips Guys.
I finally got around there last night and nailed the problem straight away.
To hold the pop bumper lamp in place some one used bluetac. after some hours of play the bluetac melted down the innards of the pop bumper, jamming up the switch/spring. Which in turn left the bumper on......Melted coil/blown fuse.
Some other things found included broken diodes on the flippers and wires disconnected from the left side target as it is not supposed to be working. Need help on that one.
Check out the pics...
Simon.