I never really got any answers to this over at the Analog Only forum, so I'm taking a crack at it over here.

I have a Tascam MX-80 in decent condition, and everything works except for signal path from the RCV jack on channel 7 which goes on the stereo summing buss.

If interested, take a look at the original thread located here.

There is a link at the beginning of the original thread to the original original thread which appeared over at the Tascam Analog Forum.

The above links will better tell the story on this.

Any thoughts?

This would also maybe be a good place to cut my teeth on a recap and/or other mods, though I have no schematic...just the owner's manual with block diagram.