Pioneer SX-750 Old School Need Help. I have a Pioneer Stereo Receiver Model No. SX-750 and it just

Question

I have a Pioneer Stereo Receiver Model No. SX-750 and it just recently started distorting the sound to the speakers hooked up to the left speaker outputs and made them sound like they were blown. But the speakers on the right hand side sound fine and when I disconnect the speakers on the left and hooked them up to the right they worked fine. Any ideas?