Question VGA image error ZJ050NA 08C

[Fly_5]

Hello, I am trying to get VGA output from the Ps2 model 90004 and I get the image displaced I have connected all the cables (I think) that in place, but I think there is something that I left that makes the image is not centered, someone could help me? greetings

 

[Lightning]

Have you tried grabbing the H and V sync from pins 22 and 21 on the other side of the DAC? The logic level on the input side is only 1.2 volts.

 

[Lightning]

Might be a good idea to use resistors on them as well, 75Ω should suffice, same as ones on the RGB lines

 

[Fly_5]

thank you very much for helping me I will follow your advice and report back to you.

 

[Fly_5]

Have you tried grabbing the H and V sync from pins 22 and 21 on the other side of the DAC? The logic level on the input side is only 1.2 volts.

Do you mean to take the H and V points directly from pins 22 and 21 of the video DAC ?

 

[Lightning]

Yes, you'll need to solder directly to the chip legs, but you seem pretty skilled!

 

[Fly_5]

"H" in PIN 22 and "V" in PIN 21 ? are you sure ?

 

[Lightning]

Pretty sure, but you can look on page 11 of the 70000 service manual for confirmation.

 

[Fly_5]

My board is a 90004 but it has the same video DAC, I'm going to take out those points and put a 75 ohm interleaved resistor on it.

 

[Fly_5]

Is it ok like this ?

 

[Lightning]

Should be good, give it a try

 

[Fly_5]

does not work

 

[Lightning]

Try without the resistors? I only suggested them to reduce signal reflections.

 

[Fly_5]

I tried it and it doesn't work either

 

[Lightning]

That's a bummer. Sorry I wasn't able to help. Only thing I can suggest is trying to use C-Sync to get the H and V signals. A guy who called himself Ashen on the old ModRetro forum did it like that years ago.

 

[Fly_5]

It is off-centre in the ps2 menu but in the opl menu I can configure it and I can centre it. I don't understand why in the ps2 menu it is offset.

 

[Customledmods]

I don’t know where I saw a post but they used the lcd button controller to enter menu then reset settings it might re adjust the display.

 

[Fly_5]

I will try it out

 

[Fly_5]

Enter the menu but there is no reset option.

 

[Customledmods]

Is there an option to adjust the h or v, can you post picture of screen menu