High Speed
Williams, 1986I have a high speed that was locking on the left lower pop bumper on power up. I replaced the transistor, pre driver and coil all at the same time. Now the game starts and plays fine but as soon as you hit the lower left bumper the coil locks on in game play. The game also locks the coil on in coil test. Is it an issue in the switch stack? Something board related?
Go into switch test and hit the skirt for that bumper. If it locks on and doesn’t go away you know it’s the switch. However the fact that it locks on in coil test makes me think it’s something with the special solenoid section of the board.
Quoted from Jmckune:Go into switch test and hit the skirt for that bumper. If it locks on and doesn’t go away you know it’s the switch. However the fact that it locks on in coil test makes me think it’s something with the special solenoid section of the board.
That's what I'm thinking. I had 2 7402 s on hand that I swapped in but haven't tested the board again yet.
Update with both 4702s replaced Now the coil only fires when the transistor is grounded, does not fire at any other time.
One of the 7402s blew up. Transistor locked on. Coil locked on again. Gotta be further up stream. 7407? Pia?
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Enfield, CT