NEC FE1250 Shortening top and bottom

[jonnyques1]

Hi I know when the sides cave in it pincushining. What do you call it when its the top and bottom that starts to narrow? I have a FE1250 Multisync. It is now intermitantly compressing the top and bottom 1/2" of screen the returns to normal. This compression lasts seconds before going to normal. There have also been some random horazontal flickers.
Anyon have and idea where to look? I'm thinking it could just be a cap going bad? I dl the schematic, just need some direction on what may be at fault. Iv also thought of looking for cold solder joints on the flyback, but the problem happens when it warm not cold.
Any ideas would be great
Thanks

[Guest]

Cold solder joints are when the solder was applied too cold. This is because the larger components take away the heat from the solder bath during manufacture. If the temperature was increased then the smaller connections would be overheated.
Broken solder joints would be a better word, these happen when a component runs hot and expands, then is turned off to cool and switched back on again. This causes the solder to fracture.
Check for broken solder joints around the verticle output IC.


Let us know what you find.