I have this unit which changes size from time to time. Almost like a slight zoom in and then zoom back out. The picture is great, I have redone all cold joints, looked for bad caps, not sure what is causing this.
This can be mostly from the power supply not being stable, or the HV multiplier module is going defective.
You can verify the power suppy, by monitoring its voltages with a DVM to start with. If the supply is stable, a new HV multiplier module should be tried. If I remember correctly, this module is part of the flyback assy.
It may not be worth to service this monitor.
Jerry G. ======
I have just found where the problem reside. behind the flyback and close the board at the back, there is a little added cct board when I move it, the size changes. I suspect the problem reside there.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.