Pinball techs - please help with sound question

smalltownguy2

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I am working on restoring the sound to a Bullseye / 301 pinball machine I have. When I purchased this pin, it was missing the sound PCB, and I was lucky enough to find a pin owner through RGP that was willig to loan me his board. I've hooked up the board in my pin, but I'm having a problem.

At first, I tried plugging the speaker into J3, circled in red. I heard nothing, even though the connector has a small sticker on it labeled 'speaker.' Adjusting the volume pot (orange square) does nothing.

Currently, I have it hooked up like the picture shown below. I have sound, but it's very faint. My speaker is plugged into the connector circled in yellow, which is J4 on the schematic. Plugging into that connector gets me faint sound, but adjusting the volume pot on the pcb does nothing.

Looking at the schematic for the sound module, it would appear that J3 is the speaker connector (red circle), and J4 (yellow circle) is for a remote volume adjustment pot. I have no such pot installed in my table.

So my question is this: how do I hook this up so that my sound PCB can control the volume? Do I HAVE to install a remote volume control?

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Nope, this one:

http://www.ipdb.org/machine.cgi?id=403

There is a test mode, and that's what I was using.

It does appear that there is a sound amp on the board. There's also 4 caps, which are probably original, and should be replaced. It's not my sound board, though, so I need to contact the owner to see if it's OK that re-cap it.
 
I guess what has me confused is if the other guy's game is the same as yours why does his have a remote volume where yours doesn't? Also, just to confirm, this guy told you the board did work in his game? Did you check the voltages across the caps w a DMM?
 
I'll admit, I cannot confirm whether or not the board was working in the owner's possession. He had it in storage.

I will ask the owner if the table that he had it in has a remote volume control installed.

Is there any way to jumper the connector to 'trick' the board into thinking there's a volume pot on there? Or does it not work that way?
 
I guess what has me confused is if the other guy's game is the same as yours why does his have a remote volume where yours doesn't?

Probably because his Bally table had one, and mine (formerly a Harlem Globetrotters) didn't. Remember, Bullseye / 301 is a pinball CONVERSION kit, not an original game.

Also, just to confirm, this guy told you the board did work in his game? Did you check the voltages across the caps w a DMM?

No, the board was in a table which was in storage. No, I have not checked voltages across the caps with a DMM. What will that accomplish?
 
Sorry, I didn't get to check the link you provided yet, so I wasn't aware of it being a conversion.

As for checking the voltages on the caps, I learned with my Time Warp that all kinds of things can cause problems with the sound on different games. With my Time Warp, the sound wasn't working, and after doing a variety of checks, I found out it wasn't even the sound board that was causing the problem, it was the DRIVER board! I figured checking the caps would at least tell you if they were needing to be replaced before you actually went and did that. Also, what color are the caps? Are they a newer light blue color? Or original silver or black or another color? And, do they appear to be leaking at all? If they are light blue and the solder joints are shiny, chances are they are relatively new and you probably won't need to change them out just yet.

Something is telling me your problem lies with either the sound amp on the board or simply that missing remote volume from your current cab.

Sorry, I wanted to offer you some suggestions because I hadn't seen anyone chime in on your post yet. I'll check out your link and see if there's anything else I can recommend.

EDIT: sorry I just got to go back and look at your pic too- the caps look relatively new to me.
 
This is a pretty obscure sound board - only 150 were made. I doubt that these caps were ever changed, so I'm assuming that they're original. I will change them before getting too much farther in this project.

I would like to get a remote volume adjustment installed on this table anyway, so I will get that installed and report back.
 
This is a pretty obscure sound board - only 150 were made. I doubt that these caps were ever changed, so I'm assuming that they're original. I will change them before getting too much farther in this project.

I would like to get a remote volume adjustment installed on this table anyway, so I will get that installed and report back.

Great keep us posted.

I guess if you don't get the sound fixed, you can always play spanks' way..... :D

http://forums.arcade-museum.com/showthread.php?t=192564
 
You actually found a sound board? Awesome! Wow... that was lucky.

With the speaker connected to J4 it's no surprise that the volume is low because the speaker is connected to the pre-amp. At least you know everything is working up to that point (that's a very good thing). Looking at the schematic the thing you're missing is the remote volume control and that's most likely why it's not working correctly. I would just jump around it for now.

Connect the speaker to J3 (pins 1 and 2 are +. 3 and 4 are -). Then connect a jumper wire across pins 3 and 4 of J4. That will bypass the remote volume control. If that doesn't work then your power amp or something in the power amp circuit is bad.
 
You actually found a sound board? Awesome! Wow... that was lucky.

With the speaker connected to J4 it's no surprise that the volume is low because the speaker is connected to the pre-amp. At least you know everything is working up to that point (that's a very good thing). Looking at the schematic the thing you're missing is the remote volume control and that's most likely why it's not working correctly. I would just jump around it for now.

Connect the speaker to J3 (pins 1 and 2 are +. 3 and 4 are -). Then connect a jumper wire across pins 3 and 4 of J4. That will bypass the remote volume control. If that doesn't work then your power amp or something in the power amp circuit is bad.

THAT was the information I was looking for. GAWHD I love this site. Thanks, Lindsey! I had a suspicion that was all I needed to do, but I really want to be careful with this board since it's pretty much the only one I'll ever have my hands on until I make my replacement.

I'll try jumpering the connector tonight and report back with results.

Just for kicks, I also purchased a remote volume connector from www.pinball-signs.com:

http://www.pinball-signs.com/HTML/SPEAKERS.html

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Hopefully I'll be able to confirm this board to be in 100% working condition soon, so I can get started on a reproduction. I only have 4 weeks for this project.
 

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No, I doubt there's any market to sell reproductions. This is purely a 'one-off' reproduction for my own table. But I will save the project files and make it available for future runs if there's ever a need.
 
Got home tonight, put a jumper on pins 3 and 4 on J4, and plugged the speaker into J3.

Nothing.

Does this mean that the amplifier on my sound board is not working?
 
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