There’s a fuzzy dark patch, about 4in. in. diameter, in the
centre of the screen. Also the picture is split, e.g. with a
newsreader the right-hand half is on the left and vice versa.
With more than one object on the screen, nothing can be
First get the line hold right. If the line hold control 3RV5
can be adjusted so that one complete picture hovers on the
screen (without actually locking), replace the flywheel sync
discriminator diodes (top right side). If you cannot manage
to resolve one picture, check the PCF80 line oscillator valve
3V3 by substitution and the setting of the preset line hold
control 3RV3. Once a steady picture has been obtained,
check the DY86 e.h.t. rectifier valve or, if the picture is of
insufficient width, the PL36 line output valve.