Nanao MS8-29FTB color range

[katzinator]

I recently picked up a Taito Egret candy cab with a Nanao MS8-29FTB monitor.  While for the most part, the image is pretty damn good (no burn in, etc), The darker end of the color spectrum seems to be a bit green-tinged.  Sure enough, when going into the color setup for SFA3, the spectrum I get is:



As you can see, the darker reds and blues are unable to show up regardless of how I adjusted the RGB gain controls.  When the screen is pretty bright, everything looks peachy.  However, the minute there is a darker/greyer image, it appears greenish.

This issue appears on both my CPS2 games and with the ArcadeVGA card.  Does anyone know where I should start looking to fix this problem to regain full spectrum?  Would I need a new cap kit?  Perhaps there is poor wiring and/or interference?

[segasonicfan1]

not poor wiring or interference.  Id check your gain controls to see if they are working correctly (what happens when you turn them?) and check your RGB input caps (especially green).

[katzinator]

When I turn the gain control pots, each corresponding color gets brighter.  Even with the red cranked all of the way up, I don't see any of the darker bars, the existing bars just get brighter.

How would I go about checking the RGB input caps?  Are you referring to a physical inspection or is there a method of measuring using a multimeter?

[grantspain]

i think your background colours need to come up a bit,its definately a adjustments issue-monitors rarely give problems like that and i am not aware of any issues on the ms8 chassis apart from the electrolitic cap on the neck card (10uf 250v) which could cause that.

[katzinator]

i think your background colours need to come up a bit,its definately a adjustments issue-monitors rarely give problems like that and i am not aware of any issues on the ms8 chassis apart from the electrolitic cap on the neck card (10uf 250v) which could cause that.

That is a bit reassuring to hear, as I was afraid the monitor was just plain worn out.

I'm afraid I'm pretty new to the whole RGB arcade monitor area, so I'm a bit unsure as to how I should adjust the background colors.

After searching the site, I came across this post: http://forum.arcadecontrols.com/index.php?topic=7934.0

This guy seems to be having a similar issue to what I'm experiencing (only my colors are uneven).  He refers to adjusting the "BKG" and "drive" controls located on the back of the monitor (despite his claims they didn't resolve his issue).  Are those the same controls I should be looking for?

Edit: I poked around the back of the monitor and saw two dials labelled "screen" and "focus":



Should I attempt adjusting either of those?  If so, what sort of precautions should I take as so not to explode myself with the nightmarishly huge capacitors located nearby?

Also, here is a closeup of the front monitor controls:



On a somewhat unrelated note, would anyone know what the "SS.SW" switch located in the center does?

I understand the little metal things underneath the plastic dials in the second photo can be adjusted, correct?  If so, I'd like to add that there is one labelled "B+" located on the same board as the "SCREEN" and "FOCUS" controls.

[grantspain]

don't touch the b+ as it is factory set
you can mess with all the controls on the remote board as i think there are some background controls there-if they are not there then they are on the neck card itself(there were a few different ms8 chassis made)
i have never touched the ss-switch so i don't know what it does,i will check the schem when i get to work on tuesday but i know it ain't colour related
screen volts is like a pre brightness and focus is obvious

i personally think your blue and red background are too low or the green too high
that cap i mentioned is important

[katzinator]

RESOLVED!

I took a phillips screwdriver and adjusted the leftmost three metal pots below the RGB gain dials.  Sure enough, the darker colors popped right up.  This monitor now looks f-ing GORGEOUS!  Perfect color balance and no visible burn-in.

Thanks a ton for your help.  If you ever find out what the SW switch does, please let me know.

[Thegreathopper]

SS switch is for sharpness.