NEO GEO problem, vertical lines on screen

[Capoz]

Hello to all, I'm new on this forum but I've read it many times!

I have a big problem with a neo geo 3-5 and the neobitz 2.0

I've done the complete RGB bypass, I left all the old video encoder elements



But first and after the rgb bypass I have this vertical lines, like an interference





video here
http://www.youtube.com/watch?v=oXS7oFVGTHs

Somebody have this problem? This is very strange beacuse if I take out the neobitz from inside the neo it's ok, if I put near the mainboard of neogeo this is what I have

On my other NEO, a 3-6 version it's all ok, I think is a grounding issue but I don't know where to find the solution

Help me please, thanks to all

[gray117]

I've no idea about the actual mod that you've done, but your hunch on interference/grounding would have been my guess... have you tried this on another screen or just in cab?

Perhaps its resistance based [perhaps related to sync strength] - does the original mod advise physically ripping/cutting out any part? [can understand you not wanting to do that...]

I'd be thinking that the sync is being interfered or a touch weak - on the perverse reverse it maybe that the sync stength is a touch too high... unlikely but - unrelated to neo - this as a problem/solution I had with a screen once...

I know its probably not related directly - but I don't know if any of these rgb bypass links would help you identify anything:

http://wolfsoft.de/wordpress/?p=247

Its hard to see on the youtube but I bet this bugs the piss out of you in rl

[Capoz]

Hi the mod for vertical lines of your blog is for revision 3-6, this is a 3-5
I'm going crazy, tonight for desperation I've left all the neobitz component
result? same lines on rgb (less but visible)

at this point I must solve first on the rgb line, then I can start again to put the neobitz

the situation is this now:

RGB bypass mod with 120ohm resistor on the 3 channel, 1K pot on SYNC channel

I see that I can reduce the lines with the pot of the SYNC, tomorrow I'll buy some bigger pot, 10k and more and try to make the SYNC less bright

[brentsg]

If you don't get it sorted, send JMKurtz a PM on neo-geo.com.

[Capoz]

If you don't get it sorted, send JMKurtz a PM on neo-geo.com.

Are 2 weeks that I'm speaking with Jeff, but it's difficult try to solve something from the other side of the planet!

Now I must solve the issue on the rgb line, then put again the neobitz

[Capoz]

Please somebody can try a neo-geo aes with rgb bypass on a wide tv like lcd or plasma? set the image to wide and see if you have this lines? then switch to 4:3 and see if there are again?

help me please, Fudoh I ask also to you an help!

[brentsg]

I've seen these vertical lines before, back before HDTV's even existed. I was using an s-video modded system I believe, but they were just like that on my 4:3 CRT.

[Capoz]

ok another modded system...

[JBueno MD]

I have the exact same problem when running NeoGeo and SNES Virtual Console games on an unmodded Wii via the official component cables on a Sony CRT SDTV. I really don´t know what causes that, maybe some sort of issue regarding 240p signals and component output?. Sorry I can´t be of any help.

[Capoz]

I don't know, I have this problem also on scart RGB with wide tv, tomorrow (i'm not at home now) I'll try to set 4:3 on thiw wide tv and see if it happen again.

[Fudoh]

The vertical lines which can be seen on your screenshots are signs of an unclean sync signal. On RGB Scart connections that's exactly what happens when you use composite video instead of a real sync signal within the RGBs signal.

Now there are many different NG revisions and some of them are known for their dirty internal sync even when an RGB output is used. I'm not this much into NG modding and I haven't read up on the various NG revisions. Since you've bypassed all the RGB crap inside the picture should look better, but maybe you've got on of those boards in which the signal is dirty from the beginning.

Does the Neobitz converter have it's own sync cleaner onboard ? If not that's what I would try before changing the mainboard. Put a simple sync cleaner (LM1881 or similar) before the Neobitz's input and see if this helps. Other than that, have you made sure that you're not using some kind of composite video for sync ? If you're easy with modding, try a cable from the sync signal's source you're using to the Y (luminance from YUV) input of your TV. If you get a picture, then you're using a dirty sync (if you get a color picture you're using composite video, if you get a b/w picture, you're using a luminance/sync mix usually for s-video connections).

My NG times have been over since more than a decade, but I remember the same problem and I didn't work on it very long and simply exchanged the NG's mainboard for another revision - and gone were the jailbars.

[Kretinou]

I don't know if it is the same problem but when I play with my supergun + MVS on my Samsung Led, I've the same effect. If I use my XRGB-2 and switch the DTC_Typ from "NTSC" to "PS", the lines disappears.

[gray117]

I don't know if it is the same problem but when I play with my supergun + MVS on my Samsung Led, I've the same effect. If I use my XRGB-2 and switch the DTC_Typ from "NTSC" to "PS", the lines disappears.

Out of interest - any idea what PS means - pure signal? ... probably not being jap rather than eng...

[Fudoh]

PS stands for Playstation. It's meant to reduce dithering caused by the composite sync in the PS1's RGB signal (from the official english Micomsoft manual).

[Capoz]

Dear Fudoh, I've solved on RGB with the sync cleaner, but there is nothing left to do on neobitz, every thing that I've tried to do make this lines.

the strange thing is that if I put the neobitz inside the neogeo over the mainboard i see this lines, if i put neobitz out of the neogeo, the lines disappear, it's like an interference, a disturb but I don't know how to left it.

Thank you, I still try to find a solution