Quoted from ThePinballCo-op:I read your post. I checked for loose wires. I am ordering diodes because of what you said.
To reinforce what you said above, and other replies have indicated......the best advice I was ever given in learning to repair pins (and cars, tractors, motorcycles, and, and, and....) is do not be in a hurry to start replacing parts. Spend your time learning proper troubleshooting techniques...and the employing them. This eliminates adding another variable of a "new defective" part. It happens, frequently. Read as much as you can and ask questions here (as you are doing) and you will be well on your way to getting these issues resolved.
Good luck with your repair and let is know when it is remedied.