[asic_ace]

So, I found that the "G" board (power supply) could be removed with the power cord attached. I put it on a bench and only needed a meter. R607 was open (blown) & both transistors (NPN) in IC601 were shorted. After replacing both I soldered a jumper between "Standby 5V" & "Relay" and all the voltages were good. So I'm back where I started with sound & intermittent video. Heating board "A" no longer brings the video back so I'll remove it (many connectors) and touch up all the solder joints and look for cracked traces around the vertical drive (IC561); shooting in the dark. I could really use a scope here but board "A" cannot be removed and the TV weighs 183 pounds and is in a cabinet 5 ft. high with just enough room to rotate it; it's not coming down.

The only thing I would have wanted a scope for would be to measure the frequency that the IC601 transistors oscillate at. Sony used this design to allow using smaller transformers. The higher the frequency, the less iron you need.

I'm posting this for reference: KV-35s40 (and similar) blown power supply, first try replacing R607 (0.1 ohm fusible resistor) and IC601 (a pair of NPN transistors with a bizarre pinout). R607 looks like it doesn't really protect anything aside from melted traces (a good thing) or possibly the rectifier bridge preceding it (a better thing). The transistors in IC601 shorting (bipolar always shorts) is the primary cause.

Using a meter, if R607 doesn't read zero ohms, it's bad. If either transistor in IC601 read very low ohms (collector to emitter) it's bad. Usually both are bad.

I've found that the service manual is easily available for download from several sources; do a search.

This TV is obsolete; I hope someone, some day finds this useful.