The fault on this set consists of foldover at the left-hand
vertical edge of the screen. On change of picture format this
foldover often moves to the centre of the screen, causing the
picture to break up. The fault is present on both systems.
By changing station or adjusting the hold controls the break
up can be corrected but the foldover persists.
The trouble is due to inaccurate line phasing. This should
direct attention to the reference pulse feedback from the line
output transformer to the flywheel line sync discriminator
circuit. Check the resistor (3R2 or R32 depending on circuit
drawing) in this feed line: it should be 47kQ. If this is in
order you will have to check the associated components,
including the discriminator diodes and the PCF80 line
oscillator and its associated components. (Bush TV141