If your amp is hesitating putting out power to one channel, then the power supply (likely the caps) are on the way out.
“Serviced” means many different things to different people. I’ll give you a couple of examples:
More years ago than I care to think about,
my first “real” job was managing a shop that did repairs and bought and sold used gear on the side. All of the gear was “checked out” by me. Does it work? Does it look good? Yes? Does it have issue- like noisy controls? No problem. I’d open it up, and hit it with some tuner cleaner. Problem solved. We’d sell our gear as “professionally inspected” with a 90 day guarantee. Would I accept a piece of gear like your Sansui? No. We’d have to run it through the shop. That would kill my profit margin.
Years later, I found myself in sales and finance for a VW dealership. We sold Factory Certified used VWs. To the public, that means the best of the best, right? Nope. The cars would have to fall into age/mileage requirements. The dealer paid for a warranty from VW. Shazam! It’s certified. So that 100 point check? We’d check the oil. If it was clean on the dipstick, it’s good to go. If not, we’d change the oil. Of course, a detail. The joke when you bought the car (besides the $3000 you paid for a $300 certification) was “Two down, 98 to go.”
There are good shops and good dealerships- ask me about the $5000 of repairs my dealership just did on my Alfa under warranty- with a free Alfa loaner. But you have to have some understanding of what you are dealing with. Most people don’t.
These days, I’m not fond of most vintage gear. The prices have gotten ridiculous. I’d recommend you buy a NAD 326BEE V2 to replace your Sansui. That’s where I’d start. I’d not spend the money to properly bring the Sansui up to snuff.
