Need to start another thread!
The yoke should have never been removed
A waste of time. On this thread!
When the problem was on the chassis!
And from my experience.
Your chassis
Need to have a fixed image in your thread
like a game board crosshatch pattern
which will make it easier to see more of a width jitter
not on a game screen shot, with a video of the symptom
if you can do that.
It would be much easier if you had a O-scope
for this type of symptom..
At the same time you can confirm the width fits the
full deflection, and not over-scan causing a jitter..
And can test each resolution as well for on screen display
all part of the evaluation!
Check it out