"mlv" wrote in
:

Our Sony 14" KV-M1420U television has suddenly lost its colour.

The picture is still perfect, but in monochrome. Sometimes the colour
will return if the television is switched to 'off' or 'standby' and
then switched back on. When the colours fails, it changes instantly
from colour to black & white, as if a switch had been operated. There
is no gradual fade.

This is usually caused by trimmer CT332. You can either clean and adjust
it, or replace it with a 15pF capacitor.