JPac not displaying video correctly

[Kiwi]

Hi guys, so I tried connecting my JPac to my Sega Blast City a day ago, but when I turned on the machine all I got were some multi-colored vertical wavy lines. I turned off the cab immediately just in case the signal was bad for the monitor, so I don't have a picture. If it's not going to hurt the monitor at all I can try to set it up again and post a picture of the problem.

I'll give you my whole process so you can see if anything is wrong:

Place one jumper on the 31khz section.

Plug it into the Jamma harness.

Attach the JPac to a USB 3.0 port and to a VGA port on my motherboard because my graphics card doesn't have a VGA port. (Also, I enabled those ports in the bios, so that's not the problem. I do have a DVI to VGA adapter laying around that I can try if you think that plugging it into the graphics card could help)

Now, with a separate monitor, I set the resolution of the cabinet's monitor to 640x480 60 hz in the display adapter properties before turning it on. (Image of the option I chose shown here:

)

With the computer running and the second monitor still plugged in, I turned on the cabinet.

 

[rewrite]

Is the Blast set to 31k as well?

 

[twistedsymphony]

Is the Blast set to 31k as well?

^Check this first.

but I've found that even setting your PC to 640x480 60Hz doesn't necessarily mean it will sync on a 31KHz display.

also the jumpers on the JPAC are to be set based on your monitor's compatibility, not your PC's output. all it does is disable the sync signal if it's out of the range to help protect your monitor... so if you have a tri-sync monitor you can leave all 3 modes enabled.

 

[Kiwi]

Is the Blast set to 31k as well?

It should be, my 60 in 1 only works on 31khz. I don't know how to manually adjust it though. Also, although it is an autoswitching monitor it doesn't seem to actually switch automatically (since my 60 in 1 displays a split image on 15khz). Here's a picture of my remote board; it has no dip switches.

Spoiler

 

[tonyt76]

If you plug the vga cable from your blast city's monitor directly to your motherboards vga port, do you get a clean picture?

 

[Kiwi]

If you plug the vga cable from your blast city's monitor directly to your motherboards vga port, do you get a clean picture?

Yep, I just tried it and it works

Strange, that should have been the whole purpose of having a 31khz option on the JPac

But anyways, it works. One last question: I heard that just putting a normal VGA cable in there and using it for an extended period of time is a fire hazard, so you need to pull out this pin to stop if from sending +5 volts to the cabinet. Is that true?

Spoiler

Also, if so, which side needs that pin removed? The PC side or the side that connects to the monitor VGA (or both)?

 

[thomas3184]

Im guessing blast monitor takes separate h/v sync, jpac combines them. You can pull pin 9 on the pc side of you want to be safe.

 

[rewrite]

Also, if so, which side needs that pin removed? The PC side or the side that connects to the monitor VGA (or both)?

Doesn't make a difference. Removing either side will sever the connection.

 

[Kiwi]

Alright, I got it to display video once I took all the jumpers off the JPac and used the monitor VGA after snapping off both pin 9's on my cord. Now I have much more minor problem, There are some lines arranged in a rectangle that slowly move down the screen. My camera is crap, but you should be able to see what I'm talking about in the image attached.

Spoiler

I'll just assume it's another reason why I need to recap this thing for now.