CGA to VGA converter help needed

p1001

Well-known member
Joined
May 23, 2007
Messages
1,934
Reaction score
352
Location
Illinois
Trying to hook up a GBS-8220 CGA to VGA converter. I'm a bit stumped on how to get a picture. I can get into the menu just fine but can't get 2 different known good JAMMA boards to work.

Resolution is set properly at 1024 x 768
Input signal is set properly to RGBS ( and I've tried RGBVS and Ypbpr also).
Auto scan only produces a garbled and frozen picture.

Tried both the P3 and P11 input connectors.

What guidance can you give me?
 
I didn't get mine to work either

I tried this as a way to get around fixing a MED-RES for my Super Sprint and couldn't get it to work either. I was able to use the component signal to work from my xbox but never the CGA. I tried both horiz and vert sync along with just composite sync. I gave up and fixed the original display.

When I started this project the game booted up, now that the monitor works there seems to be a sync or timing problem with the CPU.

GRRR... I wish you luck, if you get it working post a reply with the magic.

I opened a help ticket with JAMMA, no reply yet.... 2 months and counting.

Good Luck.
 
Thats the same one i have, or at least looks to be- i can tell you on the ones i have, you have to connect both the yellow and gray sync wires on the converter to the sync signal from the jamma pcb. I'm using connector p11, btw.
 
Tried both the P3 and P11 input connectors.

On P3 it's pretty simple as there are only 5 pins, red, blue, green, ground and sync. JAMMA outputs exactly that with the sync being a composite negative.

P11 has 8 pins so there are a few more options. Red, green and blue are obvious. The other 5 pins are labeled S, HS, VS, GND, GND. The 2 GND pins are ground so that leaves me with 3 pins for the sync. (Again, I'm using a JAMMA board which outputs combined negative sync) The harness supplied with the adapter has connection points at S and VS. I tried putting sync to both, and either pin individually. I moved the S connector over to HS and tried the combo of VS and HS as well as HS by itself. None produced anything but a frozen and somewhat garbled picture. Vendor believes the board may need repair or replacement and has recommended that I send it back. He's been excellent in his customer service and I hope to be up and running soon.

IMG_1194.jpg


Thats the same one i have, or at least looks to be- i can tell you on the ones i have, you have to connect both the yellow and gray sync wires on the converter to the sync signal from the jamma pcb. I'm using connector p11, btw.
 
Did you ever get this working by chance? I have been fighting mine for 3 days on two different games and cannot get anywhere.

Thanks!
 
Back
Top Bottom