Vertical scrolling issue

OldFoo · Post by **OldFoo** » Sun Nov 20, 2011 11:07 am

OK, here is my situation. I have a Naomi Jamma unit that was running on a sega i/o. I decided to switch it over to a capcom i/o and through much trial and error got it running but only by having two power supply running, the old one that powers the lights and monitor and the other powering the jamma which is in turn powering the capcom i/o and naomi. So the problem I ran into was that once I booted everything, my screen started scrolling. Well I started tweaking with the V frequency and got it to slow down, but no matter what can not get it to stop. Here is a video of me tinkering with the V freq nob.

http://www.youtube.com/watch?v=Lx3oFBA4H5U

Any clue on where to start fixing this?

OldFoo · Post by **OldFoo** » Sun Nov 20, 2011 2:04 pm

If you switch back to the old I/O, is the problem still there?

I suspect an issue with the I/O.

OldFoo · Post by **OldFoo** » Fri May 18, 2012 1:34 am

Got a similar problem with a Naomi 2 mobo. Game comes up, but has a vertical hold problem. I can get it to slow down, but not stop.

I have another Naomi 2 mobo that works perfectly, so I know it's not the game cart (Virtua Fighter 4 Evo).

What's wierd is that it happens when dipswitch 1 is switched off (31k) on my problem mobo, but the same problem happens on my good motherboard when I switch dipswitch 1 on (15k).

If I switch dipswitch 1 on (15k) on my problem mobo the video becomes scrambled.

Scrubsy, did you ever get your problem sorted out?