Digi-G, out of curiosity... what failures did your amp encounter?
Apologies for the slow reply.
It has a few different symptoms that indicate not all is right with it:
1. Overall kind of muddled sound. May have been gradually declining for awhile.
2. The need to turn the volume up considerably further than normal to achieve same listening level.
3. Once in awhile, it completely cuts out for a couple of seconds.
It may just be that the bias and offset need to be adjusted. The sound seems to oscillate between "crummy" and "crummier". It is not running hot or anything like that.
The general consensus on this model (e.g. on audiokarma) is that is has more refined sound than earlier Sansui amps, but lesser build quality. It retailed for $1000 in 1984 and was their TOTL at the time. It's the earliest rendition of their "X-balanced" design, which was carried forward through the 1990's on a number of different Japan only models. I had it fully recapped in 2008 by a tech I contacted via audiokarma, but who has since dropped out of sight.
As previously indicated, I may have a tech look it over but do not plan to dump any major cash into keeping it running. Time to move into the modern era. Looking at either Odyssey or Van Alstine, probably via the used market. But also trying to research some of the newer Class D designs.