I have an issue where half the coils on my Big Guns go nuts when flashers go. Does this in coil test and in game play. I suspect a bad relay at K1 on the CPU board. Am I right? I don't have the schematics for BG and neither does IPDB
No this is not correct. Need more info to help. If the wiring is correct sounds like you have MPU board issues. Corrosion damage? Batteries mounted off board?
Was it working before?
Do you mean in coil test when a specific flasher goes off a different coil fires? Please explain in a little more detail. Is the problem repeatable or random?
Big guns was made at a time when the System 11B MPU was being phased in, so it can have either a System 11A or System 11B board. You can find schematics for either of these boards online, by looking a comparable time period games.
I replaced q30 and q26. The problem appeared after that. It is not random. The coil fires when it's shared flasher fires, but not vice versa.
No corrosion damage. Boards look brand new.
I am having the same problem with my System 11C Rollergames. When three of the flashers fire, each one of them triggers a separate coil at the same time. Flasher #5 fires VUK, Flasher #6 fires Drop Targets, and Flasher #7 fires Cabinet Knocker. The coils work separately when they're supposed to and do not fire the associated flashers. I have 8 month old main power board, aux power board and interconnect board. When I disconnect the flashers from the interconnect board, the problem still happens. Any thoughts? Did you fix Big Guns? Thanks!
This is from Wayout440 on a taxi thread.
"Your solenoid multiplexing is broken...allowing power to both "A" (coils) and "C" (flashers) banks of solenoids. "When the bank select relay is energized, solenoid power V+ is connected to bank "C". Then only solenoids 1C to 8C can be driven by the driver transistors. There is no power available to bank "A". The "C" bank is usually reserved for flash lamps."
My guess is you have a short somewhere in or near K1 relay on the driver board, allowing power to both banks. When a solenoid driver transistor turns on, both the coil and flasher that are controlled by that multiplexed solenoid come on at the same time, because only one of them should be receiving power."
Seems relevant to your problem. Good luck.
Ok wel substitute K1 for A/c relay on Aux board. That as I stated came from a Taxi thread. And it fixed his problem. Its got to be a relay right? Can you pop open the cover and manipulate it with your hand? Maybe the relay isn't getting proper volts. Hook it up to a 12v battery see if you can make it work. Maybe your plus 12 v is low
Thanks guys, I suspect the Relay on the Aux Driver Board as well, I'm just in disbelief that I have two totally different Aux Drivers that have failed in the same way. Is it possible that something is causing these A/C relays to blow?
Grumpy - yes you are right, it's flasher #4 that's linked to the VUK and 5 is unused. The OP hasn't come back yet, I just hijacked his thread.
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