Projection TV picture collapises vertically and horizontaly

I have a Pioneer SD-P4044 projection TV manufactured in July 1990.

After it is on for a few minutes and warms up the picture collapises
horizontally and then sometimes vertically and then goes back to normal or
it will be skewed a little but almost normal. After collapising it usually
retruns to normal after 15-20 seconds and will collapise again later..

Does anyone know where I should probably look for problems in this tv? Leaky
electrolytics?

- Mike


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