Arcade Monitor Image Rolling.

[MikeAlex]

Ok guys, first post so be gentle with me .


This is my setup:

- ArcadeVGA
- J-PAC (jumpered 15khz and 31 khz) connected R,G,B, GROUNDS and HSync -
- Arcade monitor

And now the problem:

I can

[menace]

I had the same problem--had to hook up vertical sync as well as horizontal--not twisted together either.  should bring it back into place.  The split screen trick is through the j-pac but since you have an arcadevga it handles those startup resolutions just fine.

[MikeAlex]

Ok, let me get this straight: you mean that I should connect both the Hsync- and the Vsync- to the J-Pac

[menace]

I would bypass the j-pac video altogether and go straight from the monitor to the arcadevga--that way you have R,G,B, GND, H sync-, V sync- as separate and distinct wires.  I think the j-pac only has the jamma standard composite sync but i could be wrong.

you could also try twisting the vertical and horizontal into one wire--every monitor is a little different it seems--it won't hurt it, it will just look funny if it doesn't like being hooked up that way

[MikeAlex]

I' ll try this. I' ll let you know if it works. Thanks

[JoeB]

All it means is that you don't have your vertial hold setup correctly.  This is especially true if you jump between different vertical resolutions (e.g. from 640x480 to 640x288).  Look for a little white veriable resistor on the motherboard, or external box (some have this) and play with it till you get it right.

Start by just trying to get the BIOS screen to hold without rolling and then move to windows.  Make sure you never go over 640x480 resolution.


You should stick with one resolution, fix the vertical hold to that, and your problems will be fine.

I strongly suggest you do not remove the JPAC, since it has the required video amp that many monitors require.  

[MikeAlex]

Still not working.

Ok, this is what I did:

1.   I removed the JPAC and connected the PC to the Monitor directly.
Results: The image stopped rolling but the colors were bleached.

2.   I bought a VIDEOAMP from Ultimarc to try and separate the VSync from the HSync
Results: The colors were bright but the image was unstable.

3.   I kept the R,G,B, Ground wires plugged into the videoamp but connected the HSync and VSync directly to the monitor.
Results: Same as above

N.B.: For all setting I tried this:
1 VSync + and VSync- Together and HSync + and HSync-  Together
2 VSync + and HSync +
3 VSync - and HSync ?
The best results were with VSync + and VSync- Together and HSync + and HSync-  Together.

What?s left? Throw the monitor out the window?. Throw me out the window ? AAAARRRGGGG!!!!!!

Thanks.

[menace]

Instead of using the h sync + and v sync +, try ignoring them all together and just hook the h sync- and v sync - up to the horizontal input and the vertical input respectively.

so it would go like this:

arcadevga output         chassis input
R                                    R
G                                   G
B                                    B
all gnds tied together   GND
horizontal sync              H sync -
vertical sync                   V sync -
sync GND                        GND

Since you said that when you went pc to monitor direct it worked, I'm confused why putting the video amp in there messed it up.

[MikeAlex]

Thanks Menace, I' try this tonight.