COSSOR 938

The contrast control on this set will suddenly
become inoperative, accompanied by an increase in gain so that the picture blurs and reduces in size. The sound improves in quality and strength at the
same time. A picture may then only be obtained
by reducing the contrast control setting or cutting
brightness to a minimum. The resultant picture is
then very poor with little contrast at all. I have checked all the obvious components without tracing the fault.-T. Eckersley (Bolton,
Lancashire). We advise a check of the 9A8 a.g.c. valve on the
left of the lower chassis, and also its associated M3
diode on the adjacent tagstrip.