Technics 5170 no sound in left side, weird smell

[VitylVinyl]

Hey gang! I picked up a 1977 Technics 5170 a few months ago. Looked and sounded great! Then one day about a week ago all sound on the left side went out completely: front speakers (Advent Laureates), rear speakers (Baby Advent 1’s) and even headphones. There’s a weird smell and the center of the top grill felt REALLY warm.

Not sure if this helps but the rear speakers are 6 ohms and I had them running at the same time as the front 8 ohm speakers (I didn’t know they were 6 at the time).

Any help would be greatly appreciated and feel free to answer slowly and dumbed down, I’m a bit of a dunce when it comes to working on electronics.

 

[daybreak2350]

I'm sure there are other AK'ers out there who can take a more educated guess, but obvious first step is remove the cover and "visually inspect" everything for signs of overheating--scorch marks, bulged caps, blown fuses...
Based on my own experience, vintage stuff like this with original components can be expected to fail before too long ("end of life scenario") especially if run at higher levels.