GBS8220 and JAMMA Mod Issues

KevW24601

Hi everyone,


So recently I've gotten around to modding my Arcade1Up cabinet to a JAMMA Cab. With it I have Pandora's Box 6 and Tekken 2 arcade boards.


However, I've fallen into a snag with getting video output.


I am using the stock Arcade1Up monitor (M170ETN01.1) with the same LCD controller board used by ETA Prime. The PB6 works fine when I connect the HDMI and VGA straight to this controller board.

I also have the CGA to VGA Converter board (GBS8220) that I need to get the JAMMA video signal from the Tekken 2 to output on the monitor. This is where the problem starts (I have the 8220 connected straight to the 5v + Ground connections on the JAMMA PSU).


When I turn it on, I briefly get the Chinese characters that shows that the 8220 is powered but this is followed by either a "No Signal" message or else a fuzzy (or clear solid) green screen. Same happens when I connect the PB6 this way. Both boards work fine in every other way in that the sound and controls are all functional.


I tried hooking it up to my neighbour's PC monitor as well to see if it was an issue with the stock monitor but this did not fix the problem.


Would anyone have any ideas on how to rectify this? Would be very much appreciated.

KevW24601

I'm just bumping the post as I have images here to better show the problem.




GBS-8220 plugged in:







Everything powered on:







The green screen of doom that follows:

Have you got a known working jamma pcb?

KevW24601

BrownFinger wrote: »

Have you got a known working jamma pcb?

I have the Pandora's Box 6 JAMMA board and Tekken 2.

PB6 works fine when I plug the VGA straight from that board to the LCD controller board at the back of the monitor. If I use the GBS, I get the green screen.

Tekken 2 works fine in every other way sans the GBS giving me the green screen. I've been told those GBS converter boards are very fickle.

beejee

It might be something to do with the lcd controller not being correctly "flashed" for your particular lcd monitor?

https://www.reddit.com/r/Arcade1Up/comments/aaqaxc/issue_with_modding_possibly_the_lcd_controller/

Reading over that thread, I'd be very careful about nuking your monitor!

KevW24601

beejee wrote: »

It might be something to do with the lcd controller not being correctly "flashed" for your particular lcd monitor?

https://www.reddit.com/r/Arcade1Up/comments/aaqaxc/issue_with_modding_possibly_the_lcd_controller/

Reading over that thread, I'd be very careful about nuking your monitor!

This was the LCD Controller board I bought:

https://www.amazon.co.uk/gp/aw/d/B07JMLRJN1?psc=1&ref=ppx_pop_mob_b_asin_image

As I was saying, it works not a bother when I connect the PB6 straight in to the controller board via the VGA or HDMI ports, as shown here:



The green screen only happens when I specifically try to use the GBS converter to take video signal from the JAMMA harness to VGA.

As I also said, I tried hooking it up to my neighbour's Dell PC monitor because my first impression was it could have been an issue with the stock monitor or the controller board. But the Dell monitor also gave that same green screen.

KevW24601

Just bumping again to say everything is sorted.

I got a replacement converter board this morning and works like a charm. That other converter board I got was faulty.