FERRANTI 14T6

There is no raster and the sound is normal.
I have momentarily shorted cathode to grid pin on end of tube, but the tube remained blank.
Tube bias and e.h.t. are normal. -J. A. Fenton
(Diss, Norfolk). Lack of raster, normal tube bias and e.h.t. would
imply trouble in the picture tube. Check the
setting of the ion trap magnet on the tube neck
if this looks as though it has shifted in position. Adjust, only if necessary, for maximum screen illumination. Make sure the e.h.t. is correct at
the tube final anode and, if still no response, have
the tube tested for emission.