Neo Geo Component Out - Scrolling issue.

Hello, all. I'm currently working on a project that I could use your help on. I'm making a RGB to component circuit using the schematic found here:

http://www.sega-16.com/forum/showth...mponent-video!&p=484849&viewfull=1#post484849

So far, I have gotten the circuit to work on (2) Genesis systems and my Master System as well. However, when I take one of those working circuits out, and place it into the Neo Geo, I get a strange scrolling issue. I've posted a video of the problem here:



I also have a s-video mod on the same system, and the Yout from the CXA1145 works just fine. I'm thinking there's a sync in issue when the sync signal is being fed into the circuit, but I'm not entirely sure. I'm taking the unit to my school lab for testing on an oscilloscope, but any additional help would be greatly appreciated. Thanks!

What kind of monitor is that?

It's a CRT tv that I picked up at a garage sale.

So did you try pin 10 or not?

Yeah, pin 10, 11, Composite sync pin 7 on the AV out. I even tried to pull the luma/sync signal from my s-video jack to see if I got anything... no dice. I do have a couple of things I want to try that my electronics instructors have suggested, so I'll see how that goes.

You can try putting a .1uf cap on the sync before the encoder, that helps on some TVs. If your TV doesn't accept 240p then that could also be the problem.

Already put the cap on the sync line - does nothing. I even tried cleaning the signal with a 220uf cap on the Y out line - still a no go. I'm going to play with the resistor values and see what I get.

GAH!!

It was a bad resistor! Well, that, and you HAVE to tap pin 10 on the neo for sync. It won't work otherwise. As far as resistance values go, I protoboarded it with the 147 ohm, 33 ohm, and both with a 1k ohm pulldown - it makes no difference.

Problem solved. Now, for arcade quality NeoGeo goodness...

lastcallhall said:

GAH!!

It was a bad resistor! Well, that, and you HAVE to tap pin 10 on the neo for sync. It won't work otherwise. As far as resistance values go, I protoboarded it with the 147 ohm, 33 ohm, and both with a 1k ohm pulldown - it makes no difference.

Problem solved. Now, for arcade quality NeoGeo goodness...

Click to expand...

Glad you got it sorted.

You might be better picking up the RGB and sync signals before the onboard converter. Much cleaner signal.

Also for sincs, a hex invter 2 times?>