if you want free play, you can put the machine in credit mode then all you need to do it convince the game you always have credits - even when the register is 0000.
assuming you have a model 891, if you look at the register there should be a double pole zero detect switch with a white/brown wire on the middle/long blade that connects to:
- a blade with a black/red wire when credits > 0
- the other blade with a brown/red wire when credits = 0
misadjust the switch so it's always connecting white/brown to black/red and you have free play. You can test by jumpering white/brown to black red with an alligator clip jumper and you could leave it that way if you wanted. If you never connect to the brown/red wire tho the coin lockout coil is never powered so the game won't accept coins and the lockout mechanism will never buzz.
the nice thing about replay mode is you can hold the button down and the motor does the work oof quickly coining up the game to 5 coins played.
the exploded parts diagram and some info is in the bally 1100 manual and 2400 manual. Schematics are specific to the model of the machine ... which may or may not be what's actually on the plate on the cabinet below the handle. Generally tho, if you have selectable coin/credit play, you game will be probably be very close to an 891-1. What's you model/serial plate say?
schems/manuals are on
https://bingo.cdyn.com/slots/ - look in /bally_manuals/ for the manual pdfs.
there's no way to turn on all the lights since many are controlled by the odds stepper unit. You can manually step the odds unit or use a jumper wire with one end on yellow wire (30 on the schem) and other end on the lamp socket wire that is NOT the blue (20) wire.
practically speaking tho, on that game the lights are mostly general illumination (always on), controlled by the odds unit wiper position (so you can play X number of coins to turn them on, where X = [1-5]) or the lamps are the insert coin, coin accepted and winner paid lights which you'll see normally.