Bally Electronic Pinball Repair Procedures
F.O.560-1 Bally Electronic Pinball Repair Procedures for Module and component replacement manual.
June 29, 1978.
72 page manualfor the very popular BALLY (and STERN) electronic coin-op games made from 1977 to 1978.
It has two sections of troubleshooting instructions for isolating problems to both the module and component level. Includes pictorial guide and parts lists (but not schematic diagrams) of all major electronic assemblies.
One of these books was shipped in every new BALLY machine made in this era, but most seem to have disappeared just when you need them most. This is the single most useful document for taking care of your 77-78 BALLY or STERN electronic pinballl machine.