Ian, I did the test and I do hear the game playing but it's at very low volume. I tried turning the volume up and down but no change. I'm guessing since I am only testing the yellow and white wires that I am unable to control the volume as it is not plugged into the AR?
Which volume control were you adjusting? The one on the ARIII or the one on the powered, amplified computer speakers? You're using the amplifier in the computer speakers for that test... so you'd need to adjust that one.
So, the good news is that you're getting sound - the board is working fine. That was my main concern, I didn't want for you to rewire the game only to find out that the ARIII was working all along and the board needed a pokey or something.
As for rewiring for the new sound board, it's really not that hard. Look at the wiring diagrams for both games (Page 2 of both manuals, interestingly enough). You're going to have to take the plug that plugs into the ARIII's P8 connector, and take the wires out of it, and crimp on some new connectors. See on the diagram, how the APB's audio board has PSPKR and PAUX connectors. The P8 connector on paperboy contains these signals, so your new plugs would look something like this:
JSPKR
1 - P8's pin 4, brown wire (Speaker 1)
2 - P8's pin 3, white wire (Speaker 1 return)
3 - KEY
4 - nothing
5 - P8's pin 6, orange wire (Speaker 2)
6 - P8's pin 7, white wire (Speaker 2 return)
JAUX
1 - nothing
2 - nothing
3 - nothing
4 - P8's pin 2, white wire (Audio 1 return)
5 - P8's pin 1, yellow wire (Audio 1)
6 - KEY
7 - nothing
8 - P8's pin 8, white wire (Audio 2 return)
9 - P8's pin 9, green wire (Audio 2)
Now, one snag is that Paperboy calls the two channels "Audio 1" and "Audio 2", but APB refers to them as right and left. I'm calling Right "audio 1", and Left "Audio 2". If you get it hooked up and it seems backwards, then swap the inputs (or the outputs, just not both)
Then you need to power the new amplifier. This is where it might get a little tricky. Look at the schematic - notice how many different voltages that board takes. Fortunately, since we're only using this as an amplifier and not a coin counter driver or lamp regulator, we can get away with only supplying it with one supply. It takes 12vAC center tapped, and creates + and - 14vDC (unregulated) on board to power the amplifier. Since your game has already been converted to a switching power supply, we probably only have 12vDC to work with, but you have two options. Supply DC from the switcher, or supply center tapped AC from another transformer (available at Radio Shack).
The JACDC connector on the board looks like this (only relavent voltages marked)
1 - -14vDC
2 - KEY
3 - +14vDC
4 - nothing
5 - GND
6 - 12v Center Tap
7 - nothing
8 - 12VAC
9 - 12VAC
So, you either need to supply 12vAC two pins 8 and 9, with the center tap at 6, OR, supply both +/- 14v(or something close, 12v should be fine) to 1, 3, and ground at 5. Do not connect both!
Obviously, follow the wiring diagram as you go. The schematic of the audio board is on page 3 of the APB manual.
-Ian
