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Main => Monitor/Video Forum => Topic started by: skydemon on May 05, 2005, 10:40:13 pm

Title: arcade monitor colour purity issues
Post by: skydemon on May 05, 2005, 10:40:13 pm

Hi all, I have a Sega 26" monitor assembly (part 200-5112) which is a Nanao MS8-26A (www.jomac.net.au/MS8-26A.JPG) plus a mitsubishi monitor. I have been having some pretty big purity issues with it, Ive gone over it with a degaussing wand a few times which cleared most of it but there still is some red discolouration on the centre/bottom right and some green discolouration in the center. Plus the there is a focus issue in the top left (only noticable when reading text (i.e advmenu)) and a 'line' running down the left of the screen

I have put pics of this at http://suptest1.connect.com.au/mcollins/

pay attention particulary to the 2nd and 4th pic (shows the colour issues at the centre and right of the screen). Pic 3 shows the line running down the screen and the focus issues

Can anyone help at all?
Any help is appreciated!

Title: Re: arcade monitor colour purity issues
Post by: menace on May 06, 2005, 08:04:45 am

Any large speakers or magnetic sources around?  It really does just look like its been magnetized but considering you degaussed it once already it must have been pretty severe?  has it been moved recently?  Sorry I'm not much more help  :-X

Title: Re: arcade monitor colour purity issues
Post by: skydemon on May 08, 2005, 07:21:23 pm

damn I forgot to mention that... but no there is no magnetic sources around (there is the standard 6x9 speaker that come with the cabinet above the monitor though but its not really close). The monitr has been moved but I had this issue before I moved it as well. Its been suggested that the yoke could be loose or the convergence rings have mis-aligned. So ill check those tonight,

Does any one else have any ideas??

Title: Re: arcade monitor colour purity issues
Post by: MonitorGuru on May 08, 2005, 09:52:08 pm

I have seen speakers above a monitor affect a monitor in a Midway (e.g. pacman) or Stern (e.g. SuperCobra) cabinet. However a good degauss with a professional wand usually removes it.

At least, try to remove the speaker for a couple days and degauss again to rule it out entirely.

Have you tried to degauss the metal frame and mounting bolts? You will need to remove the bezel and get up against the frame to ensure you degauss it.


Finally, it is possible if the monitor or cabinet was dropped or otherwise roughly handled, the shadow mask may have gotten warped inside the tube. I've seen it happen on new consumer TV's shipped across the country before, so it does happen, though they are usually a bit more sensitive than 25 year old tubes)


Also you may have convergence or other issues that require reconverging, or using metal tabs or specifically oriented magnets to deflect the yoke in the corner