Tapper sound problems

Vectorman

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Guys, I hope this hasn't already been asked and answered a million times. If so, please direct me to the thread. I searched for hours and can't find an answer.

Anyway, I have two tappers with this same sound problem. They work and play most of the sounds, but a handful of sounds are missing. And another handful of sounds play, but start with a loud clicking noise.

Both boards pass the channel test with all 6 channels. Both boards have tested good eproms. When testing the sounds in sound test, same thing - most work, some don't, and some start with a click.

Before I start shotgunning the whole board to find the problem, I thought I'd ask here are you guys know more about this stuff than I do.

Any suggestions would be very appreciated.

Thanks!
John
 
are you able to grab a video of this? I'm intrigued. also are you using the original linear power supplies on both?
 
I'm using the MCR power adapter with a new happ switcher. I don't think it's causing the problem, because I have a third Tapper boardset that I can plug into the same cabinet, and it works perfectly with all sounds and no clicking.

However, one difference is that the working one is an original SSIO and the clicking one is an SSIO w/ panning.
 
I also have a spy hunter (similar hardware) with nearly the same issue. Explosions sound more like the sound board exploding.
 
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My Tapper cocktail is also doing a popping/clicking noise when certain sounds are triggered. For instance when pouring a beer, throwing the mug in the air, and when the bird is flapping.
 
Yes, those are the same times mine makes the clicking sound. I hope someone chimes in with the answer, but in the meantime, I just stole a couple of sound boards off of some Two Tigers boards I had and am using them - they work perfectly with no clicking.

But I still want to fix the original ones if anyone has the answer....
 
Just wrapped up a ton of Bally MCR boards. Here's my advice:

When troubleshooting a problem like yours, I use a set of amplified PC speakers, the cheaper the better as you'll have to cut off the input plug. The male input plug for the speakers I cut off and strip that cable. You should then have 3 wires: right channel input, left channel input and shield(ground). Splice a test clip onto the shield and clip this to the ground on your sound board. Splice a test clip either the right or left (doesn't matter which one) input wire to the speakers and this wire you'll use as a probe to detect sounds on the sound board. Be sure to turn the volume on the PC speakers all the way up.

With the game in test mode, select the channel test. This will force all 6 audio channels to produce tones alternately. Now use your homemade probe and probe pins 3, 4, and 38 on both of the AY-3-8910 40-pin PSG chips on the sound board(located at F6 and F7 I think). On a working board you should hear tones on all 6 of these.

If you're hearing a tone on all, then your problem is after these ICs in the circuit. If one or more tones are missing, the corresponding IC of the missing sound(s) is probably bad.

Hope this helps!!
 
With the game in test mode, select the channel test. This will force all 6 audio channels to produce tones alternately. Now use your homemade probe and probe pins 3, 4, and 38 on both of the AY-3-8910 40-pin PSG chips on the sound board(located at F6 and F7 I think). On a working board you should hear tones on all 6 of these.

If you're hearing a tone on all, then your problem is after these ICs in the circuit. If one or more tones are missing, the corresponding IC of the missing sound(s) is probably bad.

Hope this helps!!

I appreciate the tip. This will be helpful on other MCR sets. But on this one, all 6 channels work fine going through the game speaker in test mode. They sound perfect. It's just that a few sound effects are missing and a few have a loud clicking sound.

thanks again, though!
 
I just fixed a boardset with a similar issue, adding results here for posterity.

Some sounds worked fine, some sounds were missing, or just resulted in loud clicking noises.

The six 74LS191 at F3-F5,F8-F10 act as filters for some of those sounds, and I wasn't getting a clock on pin 14. I traced it back and pin 13 on D13 was floating. I replaced D13 and all sounds are now working.
 
I just fixed a boardset with a similar issue, adding results here for posterity.

Some sounds worked fine, some sounds were missing, or just resulted in loud clicking noises.

The six 74LS191 at F3-F5,F8-F10 act as filters for some of those sounds, and I wasn't getting a clock on pin 14. I traced it back and pin 13 on D13 was floating. I replaced D13 and all sounds are now working.

Thanks for adding this! I will pull my board and check that. Awesome!
 
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