I'm in the perverbial jungle here, its hot! That is - the right side of the color board closest to the horizontal output tube. Oddly, this chassis appears never to have had work in this area
, between the two 6GY6 and two 6GU7 tubes. Even those two brown jumper wires are intact, but with the usual black slime and green crud at the ends.
At first power-up and after testing all tubes, the HV came up and 6JE6 cathode current was 170 ma. But no raster (video). Then the 270 ohm 3 watt cathode resistor, common to the R-y, B-y, G-y triode sections of the 6GU7's smoked and lit up. It was after I replaced this resistor and 3 more plate resistors AND grid coupling caps, that I powered up again. This time, I left the 6GU7s out and the resistor burnt up again.
Now for the strange part. I put a larger resistor, 300 ohm wirewound 10 watt in and powered up slowly on the powerstat, noting the resistor did not get hot but I saw arcing around pins 8 and 9 of the left tube 6GU7 (R-y, B-y) socket. I figured the tube socket was bad and desoldered it out and then I saw the brown wire was burnt open in the middle and arcing at socket pin 8, the cathode connection. I thought this was a heater filament wire jumper, but how could 6.3 volts short to and fry a 270 ohm 3 watt resistor?
I better get good at this, there the customer's other combo's 16 waiting for repairs and my two CTC12's behind that.