No sound from sound board

[st1300]

Have a sammy betty boop has no sound on one of the upper speakers I can switch them around and so I know both speakers work but seems to be a bad out put from the sound board it is the left speaker facing the machine, Can any help or point me in the right direction to fix this ???

[st1300]

Lucky me I found the problem, When I unhooked the speakers a while back to pads some pading to quiet them down untill I got some trimers I had turned the speaker up side down and pluged it in to the wrong spot on the sound board It was plugged in to a 3 prong connection instead of the 2 prong,
Kiss My ^$$.

[yose]

Trace the left speaker wires back to the sound board and see if they are loose. or bad wires, sometimes the wires get brittle and break inside the insulation.So try running new wires to test the left channel temperary just to see if the wires are bad.It can be a bad volume switch too. Go for simple tests first then work in from there.