The speaker connection is fine and i really dont know what you mean by the tape monitor loop
Both a and b channels do not work. Ive just been using the tuner as i have been and there just isnt any sound. No settings are out of the ordinary. Everything is what ive had it on for quite some time. I turned it off after it working as normal, came back a couple hours later and schockingly there was no sound.
I have found out that unit has two tape monitor loops. I bet at least one has become engaged. I can't find a picture of one that I can read to tell you which buttons they are on the front panel. A tape loop is designed for off tape monitoring while recording from one of the other inputs. A lot of open reel machines were three head, and a few expensive cassette machines. When engaged you could listen to the recoding just after it was recorded, as the play back head was just to the right of the record head. If you engage a tape monitor button when there is no recorder connected and actively running in the loop, then you have no sound.
Look for the buttons that say Tape MON in/out and make sure one is not pressed in. Chances are high that is your problem. Just one engaged will give you NO sound.
It is possible the label is different from what I suggested, and so you will have to use some common sense. Do you have the manual? If so read it, and it will explain about tape monitoring, and where the buttons are.
If all else fails, then take a picture of the front panel that allows us to read the labels on the front panel, and we will tell you where the button are.
