The warranty has been written for Commercial use. True route operators have a service crew to repair things that break. Moving parts break. A steel ball hitting things will eventually cause them to break. Those playfield parts are typically not warranted.

Commercial route operators expectation is that the control circuitry will be trouble free for 2-3 months while the machines rake in serious money. After that, it's pay-as-you-go for parts and possibly labor if the operator is not capable of repairing their own circuit boards.

With Bally, Williams and Gottlieb EM machines, Motors had a generous six-month warranty. Everything else had the Taillights Warranty.

With the first Solid-State games, the distributors warranted circuit boards for 90 days. That was it. We'd have coil stops breaking immediately on Gorgars and Time Warp etc. Distributors were happy to sell replacements. Also the associated fried flipper coils. Same for failed drive transistors and stuff, they would repair the board (Sorry, we're backed up, ten business days to fix) and the fried coils were not covered. We'd replace the transistors and fried resistors to get the game making money.

With early Solid State games, the distributors (real distributors who sold multiple product lines, had a staffed service department and a well stocked parts department) unboxed games and set them up and prepped them. NIB games needed adjustment and sometimes part replacements.
If an operator did not want to wait but immediately pick up a game as it came in from the factory to the distributor; the operator assumed responsibility for any repairs and adjustments and that included faulty parts if it was not a circuit board.
Even if you did not want the distributor to unbox and set the game up, the distributor service department technician would go out into the warehouse and discreetly cut open the box to put the distributor tags on each circuit board and sealed the box back up. This was because the Distributors would only work on the boards that they sold under warranty. There were protected territory rules that some unscrupulous operators would find a workaround and get games from a different geographic region distributor.

New pins almost always had a gouges on the playfield in a spot or two from an errant air screwdriver or drill gone amuck. On real bad marks, we (on the Operator side) would touch them up using a few basic paint colors we kept. Or just blacken the raw wood with a magic marker.

I've worked for Bally Midwest in Livonia, Michigan for a brief period of time in the service department. There were at least 12 service technicians there working full-time.