Hey Nino back in the "hey day" of pinball's did they have techs that did certain areas say East/west and so on? in other words how did they know a machine had an issue. Also our coke machine at work is connected wireless to the net and when the coke gets low it apparently lets coke know and they send a guy out to refill, why cant pinball's let someone know there's a fault via the net ?
Peter 
The only board repairers were at "Leisure and Allied" - They had some Electronic Technicians who used to repair boards. This would be late 70's when the SS machines were released. There were plenty of field technicians that worked for operators with varying experience. Board repairs were never done onsite, and almost all we had in operation went to LAI. If my memory serves me correct, one of the technicians was Russian or another nationality nearby.
EMs were different. Technicians didn't fix EMs - "Mechanics" used to fix them ! That's what they were known as. These guys knew EVERYTHING about EMs, Juke Boxes (valve) and Bingos. My Father and Uncle were very knowledgeable in this area. Mechanical and electrical. Electronics was left to Technicians at LAI.
Operators did have a "gentleman's agreement" about locations. My Father's route was North of the city - Carlton, Brunswick, Reservoir. He had some country locations and he was operating in as far as Woolongong in the 50's and 60's as there were no operators in NSW (yet). Some of his Billiard tables, Soccer Tables and Bingos were left up there as he grew tired of driving up there. But this is very early on in the infancy of coin op in this country. He focused on Cafe's "Wog Shops" as there were no arcades - they didn't exist except at places like Luna Park. Hamburger Shops, Take Aways and even Milk Bars. He owned one Shop in Edwardes St in Reservoir that used to have a dozen Bingos, 6-7 pinballs and a Juke Box. That was the closest thing to an arcade in the 60's.
These days, anyone who can hold a soldering iron is a Technician. But back then (60's - 80's), they were Mechanics and Technicians. These guys knew their work.
