Neo Geo Monitor issues

lopan2008

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Recently picked up a Neo Geo MVS 2 slot cabinet. When powered on the monitor presents with two issues. First, the right half of the screen is lighter than the left. Second, the screen has a wavy effect that travels from the bottom of the screen to the top (reminds me of heat rising off a road). It doesn't effect the color other that the fact it seems to be linked to the right half of the screen being lighter. Gameplay is possible and after a while you don't notice the screen issues, however, I want to remedy the problem so that it doesn't worsen in the future.
Having worked on this machine prior to adding to my collection I do know that this problem started several months ago. The first time it was noticed was immediatley after installing a Metal Slug cart. Not sure if that was the culprit or if it was just a coincidence. I have disconnected and re-connected all the connections to the monitor and even tried disconnecting the monitor ground since it is mounted to the chasis (has been know to cause screen distortion in Q*bert machines). So far no luck. Any advise or guidance would be greatly appreciated.
 
Do you know what type of monitor it is? I have a kortek that does the same thing so I'm curious if yours is the same. It has a fan over the flyback. The schematics for it also appear to be non exisant.
 
If it's a dedicated Neo it most likely uses a Wells Gardner K7000. Common problem with those is bad caps that can cause your issue. There are two in particular that commonly go bad in the power supply section. They are (iirc) 47uf@160v and 22uf@160v. Both are located near the fuse. I don't have a board right here in front of me atm. You can do a full cap kit if you like, but usually all I've had to change is those two, and that more often than not will correct your problem. Start with that, and go from there.
 
wells

If it is a wells 7191 or equiv. replace 47uf 160v cap and the 22uf cap next to the regulator.
actually you might(with the power off) able to move the 47uf cap as one of the legs is broken.
last case would be the regulator that would cause the waving, but, odds are it is the 47uf cap.
 
"Uneven brightness" is a common symptom of bad electrolytic capacitors. I am assuming you have NOT installed a capkit and you should do so NOW then report back.
 
Thanks for all of the replies. I will look for the Monitor type/number and order a cap kit. I am currently trying to figure out how to get the back off the cabinet so that I can get to the back of the monitor to unbolt/disconnect/discharge. There is no proper back hatch on the cabinet since games and the board are installed through the controll panel opening. Once I get that figured out I will proceed with the repairs and report back.
 
Please look at the Neo Geo Cap Kit post I have up. I have pictures of the monitor chasis there. I have modified the back of the cabinet so it now opens easily, but I have yet to find a definitive model identifying number on the chasis.
 
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