Replaced Q3 tip and knocker ok. This has been a problem when I installed a knocker for the first time. Knocker is not a problem from the pf swap, I believe

 Did the test with J1 removed and game booted and pressed credit button and game started. So can I safely say the pcb's are ok and now its time to look at the pf.

What are some of the things that can cause such problems? I have done some prelims and am making sure caps on switches etc are not touching things as well. I am finding the I have missed spots on the braid where it is very loose and could have touched switch diodes. Have temp stuck these areas with masking tape to highlight the area and ensure they are away from harm.

One thing I did notice I had a target mounting plate screwed on top of a braid line. Could this cause strange things? Thanks

Braid line should not be touching anything except the related lamp sockets.

Are the CPU lamps working ?
Is the switch matrix working ?