Neo Geo bad video (green)

DaisyAge

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I've consolized another neo geo and I get a lot of green. The crosshatch and gameplay are all green when using component from a jrok rgb encoder. I've replaced DAC resistors, the LS273's and still no good. In fact, at one point it was worse and lost the blue border on the crosshatch screen all together. Any help would be appreciatedScreenshot_20190119-131938_Messenger.jpgreceived_262749824440554.jpeg
 

Xian Xi

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Check the output resistors on the JROK for Component. I’ve had times in the past where some weren’t soldered on good.
 

segasonicfan

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Problems like this arw why I always keep an RGB test monitor around. This definitely looks like a problem with your encoder and not the Neo Geo
 

DaisyAge

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This one is an MV1ACH but I've also tried the same encoder on an MV1B with the same results. I did hook up the jrok encoder to a sega genesis to see if it was the encoder and the picture seemed fine. It was a little on the dark side though..
 

DaisyAge

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they all seem to be in good order, I also tested the s video output and I got orange and black and white stripes.
 

BIG BEAR

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Test your resistor values on solder side under U9, U8 and U6 and see if they are correct.
BB
 

DaisyAge

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they all seem to be in good order, I also tested the s video output and I got orange and black and white stripes.

I believe I talked to you Xian Xi a while ago and you said it might be a sync issue? The encoder worked fine on my first neogeo but all the ones I've tried now have had color issues.
 

DaisyAge

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Do the resistors need to be out of circuit for accurate reading?
 

DaisyAge

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Everything looks within range, though I can't be 100% sure. I don't have a microscope to read the values on the resistors
 

BIG BEAR

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I didn't have to because I had another board to compare and one of the values of the resistor was way off from where it should have been but to be more specific you want to check the resistors for VID- RED GRN & BLUE at the edge connector R48=RED, R62=BLUE & GREEN= R57
I had a very similar problem BUT with an MV1B
BB
Do the resistors need to be out of circuit for accurate reading?
 
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DaisyAge

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Do you remember those values? I have an MV1B with me that has the same issue
 

BIG BEAR

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No but I can give you the values of a good MV1B and you can compare.
I'm pretty certain I had the exact same problem.
BB
 
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BIG BEAR

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OK. With the 1B, the problem was @ U6 chip(pin 6) connected to R74 or I could be wrong and it's between pin 2-8.Here is the read out I get and if something is way off it needs to be replaced.
R61- 219.3 OHMS
R60- 464.8 OHMS
R59- .990 KILO OHMS
R58- 2.122 KILO OHMS
R65- 2.170 KILO OHMS
R66- .994 KILO OHMS
R67- 462.8 OHMS
R68- 221.5 OHMS
R75- 221.9 OHMS
R74- 460 OHMS
R73- .977 KILO OHMS
R72- 2.117 KILO OHMS
BB
 

DaisyAge

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OK. With the 1B, the problem was @ U6 chip(pin 6) connected to R74 or I could be wrong and it's between pin 2-8.Here is the read out I get and if something is way off it needs to be replaced.
R61- 219.3 OHMS
R60- 464.8 OHMS
R59- .990 KILO OHMS
R58- 2.122 KILO OHMS
R65- 2.170 KILO OHMS
R66- .994 KILO OHMS
R67- 462.8 OHMS
R68- 221.5 OHMS
R75- 221.9 OHMS
R74- 460 OHMS
R73- .977 KILO OHMS
R72- 2.117 KILO OHMS
BB

Alright I had some time and checked and none of my values were more than 10 ohms off, so in my experience that wouldn't make such drastic changes. Also I should add that I swapped U6 and U7 with a set from the first MVS I consolized so that I could rule out the 273's. I believe that was a recommendation from Jamma nation X. That leaves either my JROK encoder or a bad sync signal I guess
 
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Xian Xi

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Is Svideo and composite the same or are those two signals correct?
 

DaisyAge

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never tested composite since I'd never use it but if I remember correctly svideo was orange instead of green and there were occasionally black and white lines running across the picture
 

DaisyAge

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So with all this should I assume it's the encoder? I find it hard to believe 3 mobos were all shot in the same way
 

DaisyAge

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Have you seen the JROK ones anywhere? Last time I saw one it cost twice as much as its worth in shipping
 
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