Hello Pin Folks,

I'm hoping this might ring a bell with someone less green than myself who might have some debugging tips. I have a Bally Silverball Mania I'm restoring and there's one pesky light (left spinner) that will not light up in attract mode. I've traced things back to the lamp board, all the way back to the decoder IC. If I connect the pin in question on the harness to a different (known good) transistor leg the light comes on -- so I think that clears any continuity problems under the play field. Next I bridged one of the known good output pins on the IC to the one in question -- that also lit up the light. Having that knowledge, I replaced the IC figuring it had a bad output. I put the new IC in and same problem persists.

My question(s) to the more veteran fixers out there: Having bridged a known-good output pin to the bad one and seeing the lamp come on -- does that clear everything downstream from the bad output pin? Second, I thought maybe one of the decoder IC inputs could be bad, but it would seem that if one input was flaky it would affect at least half the outputs -- it being a 4 to 16 decoder and all. Any other suggestions in terms of obvious things to check or what direction I should head towards in my debugging efforts.

Thank in advance to this great community.

God damn -- you were right. After replacing the transistor and the IC it turns out the lamp works. I just assumed all the board controlled lights would illuminate at some point in attract mode. Given that the spinner lights toggle with the 10 point rubber switches that must be the reason it doesn't in attract mode. I feel like a bit of a fool but that's the nature of fixing these things -- especially when you're a noob.

Thanks for steering me straight.