Lindsey
Well-known member
I've spent a lot of time working on System 80 but this one really takes the cake. Gottllieb basically designed their game to burn coils.
I'm working on a Gottlieb Force II. It needed all kinds of bullshit which I'll get into another time but I'm down to just 2 lamps not working. Obviously the thing to do is put the game into lamp test and start troubleshooting these lamps. The first thing you'll notice, once I get the game into lamp test is that it doesn't flash all the lamps on and off at the same time. This is not unusual for System 80. I assume they saved code space by just calling the attract mode routines from their test code as the way the lamps flash in test look a lot like attract mode. This in itself isn't a big deal until you add the fact that they're also driving several coils in the game with lamp driver circuits (basically using the lamp driver circuit as a pre-driver for a big-ass transistor mounted under the playfield). So rather than have these lamp driver circuits not flash in lamp test their code happily energizes these coils over and over again. Even that wouldn't be a huge problem over a short period of time but they're not energizing the coils for what would be a sane length of time, say 100ms, instead the coils are energized for like FIVE HUNDRED milliseconds and start getting hot within a few cycles.
They were kind enough to put a timer on the lamp test so it only runs for maybe 30 seconds but you can just push the start button to start it again. If you didn't know what was happening and ran the lamp test a bunch of times in a row you could easily burn up those coils. I don't think it's a coincidence that one of the two coils that were burnt in this game when I got it were on these kinds of driver circuits.
You can use the lamp test... but a bunch of coils will burn up as a result of running it more than a few times in a row. So you've got that going for you...
I'm working on a Gottlieb Force II. It needed all kinds of bullshit which I'll get into another time but I'm down to just 2 lamps not working. Obviously the thing to do is put the game into lamp test and start troubleshooting these lamps. The first thing you'll notice, once I get the game into lamp test is that it doesn't flash all the lamps on and off at the same time. This is not unusual for System 80. I assume they saved code space by just calling the attract mode routines from their test code as the way the lamps flash in test look a lot like attract mode. This in itself isn't a big deal until you add the fact that they're also driving several coils in the game with lamp driver circuits (basically using the lamp driver circuit as a pre-driver for a big-ass transistor mounted under the playfield). So rather than have these lamp driver circuits not flash in lamp test their code happily energizes these coils over and over again. Even that wouldn't be a huge problem over a short period of time but they're not energizing the coils for what would be a sane length of time, say 100ms, instead the coils are energized for like FIVE HUNDRED milliseconds and start getting hot within a few cycles.
They were kind enough to put a timer on the lamp test so it only runs for maybe 30 seconds but you can just push the start button to start it again. If you didn't know what was happening and ran the lamp test a bunch of times in a row you could easily burn up those coils. I don't think it's a coincidence that one of the two coils that were burnt in this game when I got it were on these kinds of driver circuits.
You can use the lamp test... but a bunch of coils will burn up as a result of running it more than a few times in a row. So you've got that going for you...
