CGA to VGA

[Brendan1495]

Hi All, I am trying to set up a cab with lcd monitor and a GBS 8200 v4.00, whatever O try to do the picture is terrible and jumps all over if I try the board I am using through a supergun on the TV its great any help would be appreciated. Pictures below

 

[Kev A]

have you got the ground connected on the video cable, mine came loose once and something similar happened

 

[Brendan1495]

Yes the grounds connected

 

[gunblade]

it could be clamp and clamp sp settings

 

[Kev A]

holding down one of the buttons on there preforms a factory reset, might be worth giving that a go, I think I also had to play with the clamp st settings on mine, and lower them to something like 04 and 05, rather than the default which is 90 something. although that was a color issue where it would gradually get more and more pink.

 

[ColinD]

Kung Fu Master uses an odd screen format at about 55Hz refresh rate, so might be out of range ?ColinD2019-04-15 14:46:45

 

[Vamino]

I also agree with the sync being slightly out of range and some adjustment to the clamp may be needed.

I messed around with mine for hours using a 24khz input and eventually got a decentish picture out of it, which wasn't too bad considering the price of the unit. I tried messing around to get the slightly washed out colours to pop but nothing helped. There was some interferrence but doing the following eliminated the remaining noise/fuzzyness.

The unit served it's purpose until I eventually bought an OSSC which is expensive when compared to the GBS8200, but I'm very happy with the OSSC and glad I made the purchase.

 

[Brendan1495]

Thanks for all your help, could anyone suggest a descent LCD monitor that would support 55Hz refresh rate

 

[sukhbir]

Why use vga?you can pick up an old crt tv and use it’s scart rgb socket.you will hardly have any sync problems .the old TVs had generous line and field frequencies.

 

[Brendan1495]

Would do but my cab is really narrow, no room for a CRT

 

[Brendan1495]

Got a CRT will try at weekend, thanks for the help

 

[ColinD]

I'm tempted to suggest that your board has a fault that has materialised during your swapping, the horizontal lines missing also worries me. Have you another different game pcb to try ?
ColinD2019-04-18 14:32:25

 

[Brendan1495]

At the moment I dont, but if I use a supergun on the TV the picture is fine no missing artifacts, but its black and white