Good repeat sources for help:

https://www.mikesarcade.com/arcade/

https://www.myplacearcade.com/index.php

https://www.arcade-museum.com/

https://forums.arcade-museum.com/index.php

http://www.arcaderestoration.com

https://homepinballrepair.com/pinball-electronics-tutorial-basic-electronics/

http://www.thepinballfix.com/tips/bally_lamp_fixes.html

http://stevekulpa.net/pinball/bally_sl.htm

http://www.techniek.flipperwinkel.nl/ballyss/rep/index1.htm