Wow this is heavy! It has 2 power transformers, one per channel, that are larger than most amps with just one transformer. Apparently the trouble started when the pre-amp gave trouble, continued use saw that take out one channel of the power section and blew the fuses. I had to fix the power amplifier's blown channel then the pre-amplifier channel that caused the problem in the first place. The power amp uses the rare and very sort after (Toshiba don't make them anymore) 2sc3281/2sa1302 output complimentary pairs, 2 of each, that is four devices per channel. If you buy them secondhand they may well be fakes. I happened to have a few on hand, salvaged and genuine. Also needed to replace the drivers and several resistors as well. After repair of the power section it was carefully powered up on the variac as I did not want to risk blowing the power output devices again...whew all good. Adjust standing current, it's quite high on these and they run quite warm. What I actually did was repair the power amp; test it separated from the pre-amp, there is a button that bypasses the pre-amp (some amps have a pair of jumpers in the RCA connectors on the back panel) then ran it up very carefully to only a low voltage with the pre-amp connected, I could hear the problem and made some voltage measurements and tests to find the problem. Getting to the tone amp/pre-amp means removing the front panel and sub chassis making live testing very difficult so diagnosing before hand is definitely worth while. Having repaired the pre-amp, it needed some dry joints and two resistors replacing, it was reassembled and retested with the variac, the voltage being increased slowly until full mains voltage reached with no problem.
Well it was definitely worth all the time and effort, sounds really good with lots of power in reserve for most situations, these will drive any speakers I would think, they really are high voltage/high current amplifiers. A final adjustment and soak test and it should be good for quite a few more years.