Twilight Zone
Bally, 1993You're currently viewing posts by Pinsider coyote.
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If you ground the metal tab of the transistor, does the coil fire?
That will test everything from the transistor to the coil. If yes, then the problem is either with that transistor or the pre-driver transistor or the address decoder on the power board. If the coil does NOT fire, then the problem is that transistor through the molex connector to the playfield.
Quoted from GRUMPY:If its a TIP, I wasn't sure if the board was original or not. That's why I asked for the number on the actual transistor.
Ah! Good point, I missed that. I'm so used to working on the older boards. 
Sorry!
Quoted from dzrossi:I am apprehensive about completing circute when powered on as it is 70 volts DC. Is there a way to test pre transistor. Is there a way to test address decoder (never heard of that) Board is a Rotten Dog after market so I assume it is good
When you 'complete' the circuit, you're grounding it, not applying 70 volts. It's a perfectly fine test, back in the 90's, that is what was done to verify problems. 
Since it's a RD, you'd have to check their schematics..
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Canfield, OH