Si-320z monitor help

[Eastbayraym]

So I got this sharper image monitor that’s got some problems
there is some kind of interference across the middle of the screen and the overall screen is waving rolls left to right
anyone know how to fix this?checked it in two different cabinets and with multiple pcbs
found a owners manual for a different model that says it could be something with the yoke
here is a video
https://youtu.be/Guhg7U0C_Tw

[Manul]

To me it does not look like a sweep problem. Maybe excessive power supply ripple? Dry capacitors?