clone noir 15khz issue

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Spectrexcwk
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clone noir 15khz issue

Post by Spectrexcwk » August 18th, 2018, 11:22 pm

I have 2 clone namco noir's. the lcd's inside are sharp LK315T3LA31. I bought them from a friend in las vegas. He hosted a weekly fighting game night on the cabs. No one in attendance ever noticed an issue with the various cps2 games.

Since I bought the cabs and moved to california, I haven't been able to get any 15khz board to look right.

Inside each cab is a vga splitter (no transcoding) with two 5 pin cga connectors for input. This is how it came from the factory, and how my friend said he had it connected during the game nights.

cps2, cps1, cps1.5, have a "wobble or rolling disortion" throughout the screen

if you look at the mountains you can see it here


also in the super turbo title screen


here is footage from my naomi, powered by its own sun psu connected directly to the lcd in 15khz mode


mvs shows graphical corruption - look at the sky. there are numerous little purple lines
Image

notes:
- all the boards play and look 100% fine on my bvm + retroelectronik supergun
- naomi image is fine in 31khz mode
- if I connect a gonbes 8200 the picture is fine. However the gonbes is laggy and looks horrible no matter how many menu settings I adjust.
- The lcd does detect the 15khz signal, but as 720x240
Image Image

I'm not sure what to do at this point. I guess I could buy an ossc. But I shouldn't need to right? These came wired for jamma, presumably ready for 15khz input. Also, my friend said he saw none of these issues.

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grantspain
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Re: clone noir 15khz issue

Post by grantspain » August 18th, 2018, 11:43 pm

maybe the video signal level is too high from 15khz

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Spectrexcwk
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Re: clone noir 15khz issue

Post by Spectrexcwk » August 19th, 2018, 12:33 am

grantspain wrote:
August 18th, 2018, 11:43 MP
maybe the video signal level is too high from 15khz
how would I adjust this?

here is picture of the cga -> vga splitter

Image

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kazuo
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Re: clone noir 15khz issue

Post by kazuo » August 19th, 2018, 6:23 am

I'm pretty sure you can't. I think that thing is just a pass-through, I'd be surprised if it did much of anything else.

Most likely you need to add some resistors to the RGBS lines - try 220ohm and see what happens.

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