Thanks to all of you for your input.

I am trying the generic route now.

Alex

AS wrote:
Where can I find the schematic for this old monitor? Packard Bell Model
1511SL, FCC Id BEJCP500

It is 11 years old and the image is very nice, until recently when I can
only use it at 640 by 480, at 60Hz.

If I try higher resolutions or frequencies the image will appear smaller
(both shorter and narrower) and I will be able to see what seems as the
retracement raster on the top of the screen.

For me it justifies to fix it as a weekend project.

Thanks for your help.