After a long, long sleep: ML-335

@terry9, @bigkidz...you guys are techs, right? I was always told that electrolytic caps age with ’"use", not with just "age". Is that true?

The ML-335 was made in 1998.  That makes it just 25 years old.  Maybe new in box or demo unit.  That's why I asked about age.

Just an amateur, but I've been doing this for 20 years. Actually, electrolytics usually go bad with heat, not use. They dry out. So, the power supply for my main amps is located in another room, a cool one, with all electrolytic caps well below all sources of heat.

Given the value of the ML piece, 25 years is pushing it too far. IMO. 

My suggestion is to look inside first to make sure that it not too dusty or any dead fauna, insects etc inside. From personal experience I can tell that it’s very common to find some dead insects inside old equipment. Clean it if needed and live it ON for a couple of hours, not connected to anything except power, observe it, smell it for any burn. If everything looks fine then clean all the contacts with contact cleaner, make sure if the specifications are corresponding with your system and connect it to the system. Start to listen from lowest volume. 

Good point, @surfmuz , dust and wildlife can be a problem. But if it's been sitting in its box, perhaps less of an issue. I would not risk an exploding electrolytic in a high value classic, but YMMV.

Take it to a Mark Levinson factory service center. Its a very nice amp when running right.