How Can We Help?
When a camera switches to a new shot with more than a
minimal amount of red content in it the whole screen suffuses with red/orange, taking about five -fifteen seconds
before the colour balance returns to normal. The fault occurs only at the red end of the spectrum, and is not affected by the a.f.c. action.
This is an unusual fault. It would seem that either a transistor in the red video channel is leaky, or that the R -Y
chrominance amplifier is going unstable. The transistors in
the red channel are Q159/Q160/Q165. Oscillation in the
R -Y chrominance amplifier circuit could be due to failure
of the collector supply decoupling capacitor C407 (0.01µF)
or leakage in the emitter decoupling capacitors C404
(10µF) or C405 (0.047µF). If you are very unlucky, the
tube could have interelectrode leakage in its red gun.