BEO VISION 3400

The picture is perfect for about fifteen minutes, then the
blue horizontal convergence curves upwards at the left and
downwards to the right. At the same time the colour goes
streaky, with grouping of the horizontal lines across the picture (with an efect like faulty aquadag earthing on a
monochrome set). With the colour removed, a perfect
monochrome picture is obtained except for the blue
horizontal convergence being out. The same fault is present
on two of these sets. Are you likely to publish a servicing
article on this chassis?
Each time we’ve met this irritating blue convergence
problem it’s turned out to be due to a faulty transistor,
5TR6 (BC114), in the blue horizontal amplitude antimodulator circuit. It’s doubtful whether putting this right
will cure the “sizzle” however, which could be the first sign
of failure of the line output or e.h.t. transformer. We have a
comprehensive guide to servicing this chassis on file, and
this will be appearing later in the year.