May 09 2014

Neo Geo – How to fix broken RGB output (missing color)

After hooking up my Neo Geo with a RGB Cable, I noticed that colors did not render properly. Image was all “yellowish”, which did not appear when connected with it’s original (composite) cable.

Neo Geo - Before Fix

Before repair – notice the green sky and the yellow text (credits)

At first I thought that the TV is faulty, but after testing RGB with some other consoles, and even testing with another Neo Geo RGB cable, I came to conclusion that the Problem must be within the Neo Geo itself.

As the Image is full of  yellow and green, the blue Color must be missing.

cmyk-rgb

Imagine a world without blue….

After opening the console, I noticed no directly visibly damage. I found some indications on the net what components are responsible for Video Output, but theses pictures didn’t’ correspond with my System Revision.

So I traced the blue signal back from the connector.

connector

Image courtesy of Tim’s Site : http://members.optushome.com.au/eviltim/gamescart/gamescart.htm

Pin 8 was the one I was looking for.

One of the Caps for the signals that provide RGB Video had leaked out. Bingo! It was the Cap for the Blue Signal.

Neo Geo - 04 - Faulty Cap

There it is !

So I replaced that one with a new one with similar values (100uF/16V) , but some sources indicate to put higher values for a better picture quality. I didn’t bother, according to this page, my System Revision already had great RGB Signal Quality.

Running first tests confirmed that the repair was successful :

Neo Geo - 07 - First test run

Quick ‘n Dirty Test Run

Neo Geo - After Fix

After repair : Sky is blue, and text is crisp white

I hope that this guide encourages anyone with a similar issue to fix it, it is a very easy repair.

More picture available in the gallery below, along other games.

Permanent link to this article: http://www.hiscorebob.lu/2014/05/neo-geo-how-to-fix-broken-rgb-output-missing-color/

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