Hi,

I've got a 17" sony trinitron which developed a yellow tint when i
switched it on this morning.

A white test image appears white for the first inch or so from the
left edge of the screen, but distinctly yellow for the rest. Also, if
i display a test image with thick black and white vertical bars, each
of the white bars will also be 'pure white' for the leftmost inch or
so, but yellowed from there on in, so it looks like it's okay for the
first 'x' amount of time after turning the gun on each time.

Does anyone have any ideas what might be causing this, or where i
should start with diagnosing the problem?

Martin.