Need help-McIntosh MA 5100

Integrated suddenly started sounding bad in left channel. Checked for source not an issue. Seems to probably be the left channel itself. Volume is lower, sound is grainy, tinny, some noise too. What would this likely be? I need to find a tech in Hawaii who does Mcintosh too?
Post in Audio Karma McIntosh forum & you may get some advise. Good luck.
The MA5100 is an old beastie . . . there's all sorts of things that could be going wrong. Semiconductors from that era frequently simply fail with age, as do electrolytic capacitors.

Specific problems that I remember from the 5100 were dried-out main filter capacitors that cause oscillation in the preamp circuits, bad/flakey slide switches, and worn volume controls.
Any older unit that has tape monitor switches - these are the first thing to check -especially if you aren't using the switches."Exercise" the switch(s) by flipping ,punching or rotating them repeatedly - if your problem changes or goes away even in the short term - this is probably a dirty contact - trying cleaning it if you can get to the switch with a spray cleaner.