I tested for AC voltage at pins 7 and 8 of J6 and got 17V on each pin, and checked for the presence of 22v on the 22vdc test point which gave me 23VDC. I have two different types of speakers for testing,the square set is battery operated and has a single wire plug end. The other round pair of speakers are non battery powered and have a dual wired plug end. WHich do you suggest I use and do I have to cut the plug off the end?
Use the speakers that are powered, as you need something with an amplifier for this test.
You don't have to cut the plug off. If you have alligator clip leads, clip them onto the headphone plug - the ground is the "ring" - the part closest to the cable. The signal input is the very tip. Ignore the middle one, that's the other signal input - for testing, you only need one amplifier. If you don't have alligator clip leads, you really should... but if you don't, then you can use some telephone wire or something, wrap it around the plug and tape it.
You should now have two wires attached to the plug. To test that they're connected, touch them with your fingers and to each other - you should get buzzing and popping noise coming from the speakers.
Connect the signal wires to the connector on the game, either with aligator clips, or by jamming the bare wires into the back of the connector plug, or whatever makes contact. J8 is the connector I was referring to earlier - the part of the manual I was looking at just calls it P8. (P8 is technically the plug on the harness, while J8 is the socket on the board... but since they're plugged together, they're one in the same, electrically). You really want to be connecting to the wires in the harness, so you technically don't need to have the harness plugged into the AR board. You can unplug it and jam the wires down into the holes in the connector to make contact. The idea is to connect the audio output from the game board to the amplified computer speaker. If you're using alligator clips, some bits of wire from a paper clip make great test probes - just jam them into the holes in the connector and clip the alligator clips to them.
Pin 1 (yellow wire) goes to the amplified speaker's signal input (tip of headphone plug), and pin 2 is signal ground, goes to the outer ring of the speaker's headphone plug.
Turn on the game and play, you should be getting game music coming through the computer speakers. If you don't, double check your connections. If you're definitely still not getting sound, then there is something wrong with the game board. If you get sound through the computer speakers, then there is definitely something wrong with your ARIII board's amp, and wiring in a substitute is the way to go.
-Ian