[Popester]

After typing in a Google search it does look like this is from '77 or '78 model year. Not sure if this used the SG613 HOT switch but they would short and take out a bunch of components. Check the HOT for a direct short, the damper diode, for a short, look for an inline fuse with a hard blow failure. HOT is usually mounted on a big heat sink and the damper diode will be near by maybe even soldered to the back of the transistor. I was thinking this was a earlier model, but they're numbering scheme didn't always make sense to me. I don't know if this has the SG613 or not but they were in the '75 model KV-1920, and KV-1722 sets. Not sure about the smaller ones. If the jug is good, it would be worthfixing as they are excellent sets and were so reliable. These sets used a HV block that was similar to a Zenith tripler. The casing could crack and arc to ground. I fixed one arcing to ground with epoxy glue and it's still working. That was on a KV-5200. It's hard to beat a Sony but they can be a bear to fix. Good luck and update as you get things going again.