"AJ" wrote in message
. ..
Effect is called "Blooming" and is directly related to the power supply
circuits not able to supply the additional current required to display the
brighter raster, you will also notice a slight de-focus of the information
when the screen decreases in size.
Eeyore" wrote in message
...


Michael Kennedy wrote:

I've had this Viewsonic PF790 19" CRT monitor for quite a few years now
and
it has been used daily since it was new without any issues. Recently I
have
noticed that large white images will cause the horizontal size to shrink
about 1cm overall. I keep my desktop set to black so if I minimize a
window
I see the picture expand or if I open a window I see the picture shrink.
It
is possible that it has always done this, but I don't believe that it
has.
Any thoughs on what might be going out?

Large white images require more current.

Clearly the supply voltage for that part of the circuitry is sagging
under the
additional current demand. A PSU problem.

Graham



Well the interesting thing is that it appears to be doing the opposite. It
is clear when a large white image is on screen, but blooms when the image is
dark.

Mike