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G.E.C. B T5348
On occasions. the picture and sound disappear suddenly, leaving a blank bright screen. After
switching off for a few moments then switching on again, the picture and sound come back. This
might happen once every few days or a couple of
times during an evening’s viewing. -J. Marshall
(Westcl_ff -on -Sea, Essex). The symptoms indicate that the circuit is intermittently going into oscillation. First check the
decoupling capacitors (0.001µF) by bridging each
in turn with a test capacitor of near value. Check
that from pin 8 of the V3 base to chassis and
other valvebases pin 7 to chassis. Check tuner
decoupling and aerial socket.