PinTech LIVE: Ep157 - Troubleshooting Power on Bally BlackJack
The Problem: Flippers That Won't Quit
Picture this: Bally Blackjack sitting in attract mode. No game running. No credits inserted. But the flippers? Fully alive.
Matthew had just brought the game back from a six-month tour starting from Texas Pinball Festival, living at Captain Crazy's Paradise and finally back in Seaside, CA... and while the flippers worked during gameplay, they refused to power down when they should. The culprit? Transistor Q15 — the little component controlling the flipper active relay.
The Detective Work
Matthew started with the schematics and a multimeter. Here's the technique:
Testing a transistor for shorts... with the game OFF:
Set your multimeter to continuity mode
Put one lead on the metal tab at the top of the transistor
Touch the other lead to each of the three pins on the bottom
Listen for the tone
If it beeps? That transistor is shorted — and that's exactly what Q15 was doing. When a transistor shorts, the flipper relay stays energized. Flippers stay live. Problem identified.
The Fix: Desoldering and Replacing
Removing a bad transistor takes patience and gravity.
Pro tips from the livestream:
Flow fresh solder onto old joints before trying to remove them — it helps
Hold the board vertical instead of flat — let gravity pull the molten solder down
Use a desoldering pump (the "sucker") or solder wick, whichever you trust more
Come straight down with the iron for best results
Matthew swapped in a fresh transistor, checked his solder joints (those happy little pyramids), and buttoned the board back up.
Result? Flippers behaved. Attract mode stayed quiet. Game ready for Seaside Championship.
Bonus Repairs: Displays and Future Plans
While the game was open, Matthew tackled a few more things:
Swapped plasma displays — The old ones had a subtle flicker your brain notices even when you don't. New displays? Clean and easy on the eyes. Replace these with PinScore 2518 displays to also help reduce the power load on your game.
Noted future upgrades:
Replace the tired rectifier board (the new powder-coated, solderless versions are around $100 and worth every penny)
Repin or replace the worn header connectors for cleaner power delivery
Consider a full ground mod if it hasn't been done yet
This game already had the important stuff: new capacitors, ground mods, and fresh traces where the old ones fried.
The Rubber Conversation: SuperBands, Silicone, and Strategy
Mid-repair, the conversation turned to rubber. Not just any rubber — how different rubbers change the way a game plays.
Here's the Lynn's Arcade formula for tournament-tough games:
SuperBands (silicone) go on:
Posts near critical shots (in-lane rollovers, top playfield targets)
Anywhere the ball hits hard and often
Spots where you want the ball to grip, spin, and come back with force
Natural rubber (the stretchy, bouncy stuff) goes on:
Slingshots
Lower playfield areas where you want chaos
Flippers (reds, yellows, greens) for maximum bounce and unpredictability
Why? Tournament players need a challenge. Keep the ball up top, and you're safe. Send it down low with natural rubber? That's where the danger lives.
SuperBands last years. Natural rubber degrades faster but keeps the game wild. It's all about balance.
Pro tip: For hard-to-reach spots (like under ramps or upper playfields), always use SuperBands. You won't have to go back in for years.
Community Tips from the Chat
Ground mods and five-volt mods were explained in detail. These upgrades clean up power delivery on older solid-state boards, reducing flicker and improving reliability.
Gravity is your friend. Whether you're rebuilding flippers in lower service position or desoldering vertically, let physics do some of the work.
The Bigger Picture: Learning by Doing
Matthew said it best during the stream:
"After doing PinTech stuff around the country and working with Phil, Eugene, and all these techs — games that used to freak me out? I'm pulling them down now. I've got the confidence. I've got people I can call. It's been a really neat journey."
This isn't rocket science. It's pinball.
Every transistor you test, every display you swap, every ground mod you trace — you're learning. You're building confidence. You're keeping the silverball spinning.
What's Next?
Blackjack is heading to the arcade, tournament-ready for Seaside Championship. Matthew's also prepping a Gottlieb Jacks Open (the solid-state conversion) with some funky issues — and Phil, Kyle, and Eugene might make a guest appearance to help diagnose.
Stay tuned.
Want to Learn More?
Watch the full episode of PinTech LIVE to see the repair in action, hear the banter, and catch all the technical details.
Got a game that won't quit? A transistor that won't behave? You've got this. And if you don't? We're here to help.
Keep the flippers flipping. Keep the community strong. Keep the silverball spinning.
PinTech LIVE streams regularly with hands-on repairs, real-time troubleshooting, and community Q&A. Follow along, ask questions, and learn with us.
Watch the series here: https://www.youtube.com/@MarcoPinball/streams