Neither picture nor sound were present on this
set (although there was a raster and a hum in the
loudspeaker) and so I attempted to bring in a
signal by adjusting L7 in the tuner unit, but with
no success. Further investigations revealed that the
resistor R242 in the tuner h.t. feed was charred
and so I replaced it. Signal strength was then
restored but while adjusting the coils in the tuner unit I must have shorted L4 as R8 burned out. I
replaced this resistor and also C14 but when I
switched the set on to receive a picture, R8 once again burned out. The next time I replaced it, I
first switched on when all stations had closed and
everything functioned normally. However, when once more I switched on during a transmission, the resistor burned out again. –C. Woolley (Crawley, Sussex).
Check the capacitor connected to the other end of the resistor (i.e. not the h.t. end) for this may
have an intermittent fault. Another case is an intermittent short in the associated tuner valve.