Working on a Bally Old Chicago. Ball Count Unit will not advance and neither will Player Unit. Have checked and cleaned EB relay and Ball Index relay switches. Additionally, in game only, the shoot again on playfield and the ball 4 in backglass lights are both lit dimly. If you actually earn an EB, the ball 4 light goes out and the shoot again lights up fully. Having a buddy more familiar with more EM experience help, but we're a bit frustrated and stumped at this point. Any pointers would be greatly appreciated. We do have the full schematic in hand.