Hi,

A neighbor was trashing an older Mitsubishi RPTV because he'd replaced
it with newer technology. He basically put it on a street with a sign
"Free for the Taking"...so I did.

I thoroughly cleaned out the unit, got a service manual and went
through the adjustments, and it now shows a pretty decent picture
(given the price I paid.)

However, I have noticed one problem with the pictu after the set has
first been turned on and for a few minutes afterwards, if there happens
to be a bright-to-dark vertical boundary in the picture with white to
its left and black to its right, there will be an uneven, splotch of
bright blue color all along the right side of that boundary, looking
almost like a bright blue, sloppily-painted thick vertical band of
color.

It will gradually stop happening, and I can live with it, but if it
turns out to be simple/cheap to fix (i.e. not involve replaced a tube),
I might tackle it.

Mainly, though, I'm just interested in knowing what is physically
causing this. Is it more likely to be that the blue video circuitry is
somehow unable to quickly drop down to black level as the beam passes
across the white-to-black boundary, or is this some physical phenomenon
happening in the blue picture tube? Could the phospor be losing its
responsiveness?

Thought someone here might be able to explain this...thanks.