Nanao ms9, vertical lines not as bright as horizontal lines in grid test

[Dion]

Hi, i have nanao in a sega cab which have this symptom. When you use crt test and choose the grid test, the vertical lines is like weaker/more dim than horizontal lines.

Anyone know what causing this? Btw, i have recap all electrolytes cap in the board, and it nothing changes.
Thanks

 

[nem]

What happens if you try to adjust focus on the flyback? There's two adjustment pots on the flyback, it's the top one.

 

[Dion]

I have adjusted it to the best, before i took the photo.

 

[Dion]

You wouldnt believe what i found. After so many days figuring out, i found the problem, well, you cant really say it is problem per se, but the culprit were the resistor divider in the rgb input.

The resistor was placed around the marked area. Each color line has 2 resistor divider.

Now, i dont quite remember which cab i took the nanao from, but the resistor divider set i found that had this problem, were using another value set. Which might be designed for another sega/whatever video system. So i fixed them with the same value i knew from good tested monitor, and voila! The picture comes perfect after recalibration. The grid test shows normal brighness for both horizontal and vertical lines.

Never knew that same nanao model has different set resistor value designed for each system. We really should take compilation notes regarding this, so people dont just swapped them around without knowing.

Regards