The problem with this set is a faint white line down the
screen, about +in. wide. It’s just off centre, though the
position can be altered by adjusting the line hold control.
The line is visible only on dark scenes, and only when
there’s picture content present (disconnecting the tuner er
mistuning away from the channel removes it).
The problem could be due to insufficient line flyback
blanking. In later sets in this series, flyback blanking pulses
are fed from pin 5 on the line output transformer to the grid
of the c.r.t., via a 3301ffl resistor (R146) and 0.001µF
capacitor (C195) in series. The components can be added
between points SC8 and SC13 on the timebase panel.