Converting a monitor from 625 to 405

[ppppenguin]

Actually it's a bit weirder than I thought. I thought it was defocusing but on more careful examination it looks like the 2 fields are being displaced sideways towards the top and bottom. What's more, the higher the brightness the worse the effect. This feels like a fault rather than a design or 405 conversion problem. I'll need to look very carefully at the sync sep and line oscillator. Just seeing the problem on a 'scope won't be easy.

Since I've more than one monitor I can swap PCBs to find out whether it's on the main or EHT board.