Hey Hey guys,
Wanted to give a bit of an update on the RGB mod of my sony trinitron KV-20m40 BA-4 chassis.
Success!
I can now boot my main pc with the groovyarcade live boot software on usb, and connect my computer, via DVI to VGA cable, to the VGA plug i put together, with the standard passive sync combiner from retroRGB.
I am going to document things more in full, but I think a misunderstanding about grounds has been causing me issues this whole time.
Sucessful screen test
boot up screen
sample game
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So its nice to know that my R G B and sync lines, as well as blanking seems to be functional.
One thing i can't quite figure out yet though.
I have my blanking switch which is essentially on/off. I thought it might be neat to have two sets of RGB inputs for the tv, so I bought a 12 pin switch, a 4PDT. I have my VGA side of things, 4 wires for R G B sync, Those are on the 1 side of the switch, and in the middle switched part, where the R G B lines go to the jungle as usual, and the sync pin is wired to the front AV 2 composite line
I wanted to install 3 RCA ports, each wired up to the other side of the switch, so that I can switch between VGA and RCA RGB, which I can use to run a ps2 in full RGB mode. I've confirmed that you can use third party ps2 multi av cables that include both component and composite, to get full RGB from a ps2 to a monitor. I took the RCA adapters, grounded a 75 ohm resistor on each color line, and included the same 910 ohm resistors on each external line like I did with my VGA port. The VGA RGB and sync lies are grounded on the tv board, and I connected that ground over to the RCA ports as well. I ran those 3 lines into the other side of 12 pin switch, leaving the 4th pin on the RCA side empty. For this sync, I thought I would just run the ps2 composite cable into the back AV1 composite port.
The result is a very poor looking picture when I have RGB blanking turned on
Blanking turned on
Blanking turned off
I think I must be missing something here. Anyone have any thoughts on the poor picture quality? I followed a lot of the standard RCA/BNC mod install videos.