Another Solid State Sinema challenge, the king of Sansui's. This is the first time I have had one in the shop. After determining the problem was simply bad solder connections, the real feat was getting it apart to allow access to the circuit board. Many cracked connections were discovered. Reflowed the connections and both channels now operate as they should. This was a great learning experience for me. Now the AU-7700 can join the list of amps that I will service. Great to see the classic amps keep on going! Hope you enjoyed this presentation by D-Lab electronics.