I got a high speed recently and there is no sound. The wire that runs to the volume potentiometer was disconnected, so I reconnected that to 1J16 of the MPU board.

Another system 11 game (Grand Lizard) has ground wires connected to 1J15. I do not have those wires. Should I have those wires?

Could someone please provide a picture of the top left corner of their High Speed MPU board, or verify that the game does not have anything connected to 1J15?

Well, that definitely helped some. I noticed that the interconnect cable was also disconnected.

I connected it to 1J16 on the MPU board, but now I have the wire for the volume control disconnected. Where should that go?

Ok, thanks guys. I now have the wires connected correctly. The black wires were incorrectly connected to the sound board.

I only get a hum from the speakers, but at least I know I'm on the right track

Sound test gives me some very low volume pseudo-car-sounding garbage

I can hear faint music and scratchy sounds. I'll take a look at the potentiometer, but I'm pretty happy with where it's at now.

Changing the ribbon cable didn't have any effect. I'll swap out the volume pot. I know that will increase the volume, and I'm hoping the scratchiness of the sounds disappears, too.

Thanks for your help.

Changing out the pot didn't really help that much. Even shorting the two potentiometer wires doesn't really make the volume very loud.

Luckily, I have one. I'm a computer engineer by day, and a sloppy drunk by night.

Where should I start probing?

Thanks for the help. I'll dig in this weekend.