I have an AppleVision 850AV monitor, which uses a 20" Sony Trinitron tube.
It was made in late 1997. Over the last year it has developed a multitude of
problems effectively making it unusable.

1. Image has lost focus.

2. Many resolutions and/or refresh rates (but not all) have developed a
proportion problem. The image at the sides is very squashed whereas it is
spread out at the centre. Some resolutions and/or refresh rates have ceased
to work altogether, even if they are not out of range - screen goes blank
and makes a weird noise.

3. Most annoyingly - the whole picture ripples all the time. The pixels
basically jitter, and the monitor emits a buzzing sound. This occured
recently and very suddenly, on all resolutions.

I have taken the screen apart and looked at the Analog board. I found a
charred bit and resoldered a couple of burnt contacts. Put it all back
together but no improvement. 1 should be an easy fix, but what about 2 and
3? I have no idea where to begin.

TIA.