I just acquired a Sony Trinitron Multisync 200ES. It is in fantastic cosmetic shape, but when I brought it home and plugged it in, the issues started. Here's the behavior:

1. I can turn it on and it shows a great picture (very bright)
2. It stays on for 5 to 10 seconds and then turns itself off and the light by the power button begins to slowly flash orange (no blink code, just a constant slow flash)
3. I've ruled out a resolution/refresh rate problem as it happens in DOS, the BIOS, Windows Safe Mode, etc.
4. When it IS on, the brightness controls only make a TINY difference when all the way up, vs all the way down
5. Contrast seems to make no difference
6. Changing geometry works as expected
7. Changing vertical size works as expected
8. Changing horizontal size HAS NO EFFECT
9. Changing horizontal position works as expected

If anyone has any tips, please let me know. I have limited experience working on monitors/high-voltage kit, but I'm willing to try. I know my way around a PCB, diagnosing logic issues, checking voltage, know my way around a soldering iron, etc.

Thank you!