John Gill wrote:
Dave:
I have had some experience with this problem on Dell/Sony GDM-17SE2T
monitors. Behind the flyback, there is a small transformer in location
T403. Mine had the number 998-11 on it.
These transformers develop small cracks in the core that is on the
outside of the windings. This somehow affects the horizontal width.
I had two monitors with narrow widths. Replacing the transformers
with ones from junked chassis fixed the problem.

Thanks John, I'd just put the D board into service position and was
about to check the B+ and associated items mentioned in Sam's Repair FAQ.

This will give me something else to look for, it might even be the real
cause, (ruling out caps, etc), since the width does not vary with
temperature, (just ~50mm too small).

There is also another transformer in location T701. This one can
develop cracks too, but it controls the dynamic focus. You can
have good focus in the center, but be out-of-focus on the edges, or
vise-vera.

Focus seems to be OK so far, though of course it hasn't gone to full
width yet.

Hope this helps...
John

Thanks again,
Dave