小弟的g420是用下面的方法修正的，用來修正螢幕過亮到回歸線可見問題，提供給你參考，不過你也已經做過Color Restoration，所以......

Problem: Sony Trinitron monitors with brightness too high. Also affects Multiscan G420 monitors and Trinitrons rebadged as Sun monitors.

The screens on Trinitron-based Video Display Units / CRTs get brighter as they age. There is no Sub-Bright adjustment on these units, and they get to the point where the front panel brightness adjustment is set to zero, and the screen is still way too bright (blacks appear as grey). In extreme cases the retrace lines are clearly visible.

Solution:

Multiscan G420:
1. Set screen brightness control to some middling value (say, 50-70%).
2. Make sure colour mode is set to "preset", "easy", or "expert". This is done by pressing the menu button, and navigating to the toolbox icon, and then the "3-dots" icon.
Once done, return to the main menu.
3. Navigate to the "three dots" icon (a different one from step 2, above) and then the "head-and-shoulderpads" icon.
This is the "image restoration" menu. This function will only be available if the screen has warmed up, which takes about 30 minutes.
If it's not warmed up, this menu selection will state, "Available after warm up", in which case, you'll just have to wait, making sure the screen doesn't turn off in powersave, or screensaver mode.
Once warm, you can select "yes" to start the auto-calibration process. This takes a few moments while it samples different settings.
4. Brightness can now be set as desired.


Sun Trinitron displays:
These are much the same, but have a different menu structure, and button interface, but the icons are essentially the same, and the "head-and-shoulderpads" icon is entitled "colour return".
BAP

Brett Preisig
John Reynolds

這問題應該是可以修正的，只是每家的螢幕可能選項不太一樣，建議你用retrace line 和brightness 加上螢幕的型號或同類型來找找。