Thanks Dave,
I am guessing that I have to cut loose the yoke from the adhesive that
is connecting it to the foam pads. Then lift it and glue it back in
place.
Is that correct?
That's usually the case, yes. Sony tend to use soft silicone adhesive
rather than rigid epoxy so you might as a preliminary test be able to grasp
the widest part of the yoke (taking precautions against shock hazards) and
lift it slightly and observe the bottom of the picture for any improvement.
If there's a noticeable improvement then you can remove the adhesive and
reseat the yoke, using the existing wedges to hold the yoke in its new
position. Once everything is spot on, then you can use silicone to fix the
yoke, but IME it's not usually necessary as long as the wedges are tight.
A word of warning- if you need to undo the yoke clamp screw for any reason,
do not overtighten it or the CRT neck will collapse with possibly dangerous
consequences to you. Tighten it gently and only enough to stop the yoke
moving under light force.
I tried attaching magnets at differnet positions but it didn't give the
results I was looking for.
I am attaching a link to the image of the yoke.
http://www.biosmedic.com/images/Trinitron Yoke.jpg
Once you've removed the silicone you'll find there's quite a range of
movement at the wide part of the yoke, and you'll also find that sliding the
yoke back slightly along the neck of the CRT will allow more movement,
though it's best not to do this. If you absolutely must slide the yoke back
slightly to allow for extra up/down movement, take extreme care that no
shadows or convergence issues are created in the corners of the picture.
Once you have improved the bowing, you may find the convergence needs
tweaking. The magnets may be of some help here.
Morse