RGB modded PCE DUO-R .... weird colors.

[FM-77]

I finally finished the RGB mod for my PC Engine DUO-R. But there's still one problem....

The colors are seriously messed up. Check this out:



What am I doing wrong? I'm pretty sure I have the R/G/B cables right. I tried some other combinations but that just resulted in even more weird colors.

I have a PAL TV. The picture I get is sharp and clean, definitely RGB output.

I am using the following:

15        RED/CHROMA in
11        GREEN in
7          BLUE in
20        Sync/composite video in

2          AUDIO input RIGHT
6          AUDIO input LEFT

18        Blanking GROUND
16        Blanking (+5V)

I tried both COMPOSITE SYNC and COMPOSITE VIDEO - I am using composite video (tapped from the original A/V plug) since that gives me picture. Composite sync (tapped from the chip) gives me an insanely flickering picture, and it has the same weird colors. I tried using BOTH at the same time (both connected to pin 20), that resulted in the same as only using Composite Video.

I used the following pinout for my SCART cable. Click! and the cable was originally a Saturn SCART cable. There's a resistor between pin 8 and 16. Perhaps that needs to be removed?

I'm clueless here. Any ideas?

EDIT: I forgot to mention, it may not look like it, but the colors are very bright and nice, so I don't think I'll need an amplifier of some sort.

[NFG]

Yes, you need an RGB amp for the duo.  There are details for it on gamesx, of course.

Next, your screen image seems to be totally lacking the colour RED.  Check your wiring.

[FM-77]

Oooh, I used some insulation tape to protect the pins on the chip where I tapped the RGB signal. Under the tape the COMPOSITE SYNC and RED wires got mixed up, so I used composite sync instead of red! Ha ha!

Anyway, I fixed that and now it works out nicely. Fully playable.



I don't think I'll need an amplifier, but the colors are pretty dark, and yet extremely colorful. It doesn't really show that on the picture, but the shades of red, green and blue are extremely strong. Bonk's Adventure looked really funky, but Ys looks fine (and that's what I'll be playing mostly).

Would an amp fix this and make it look perfect? Or maybe I should put resistors on the R/G/B wires?

[NFG]

Without the amp the total signal is weak, and when you brighten the image with the monitor, you boost the black level to grey, washing out the total image.  

An RGB amp would boost the brights while leaving the blacks as they are, essentially widening the min to max range (contrast).

Adding resistors would make it worse, decreasing the contrast.

[FM-77]

Thing is, I didn't adjust the picture on the TV at all. The picture is good, the contrast is good (maybe a little strong). And the colors - blue red and green - are extremely strong. They are almost glowing! If these three colors would be weaker, the picture would be perfect.

Take a look:





As you can see, the middle tones are looking fine, but the three main colors are too strong. Adol here is glowing blue! The lava is also much brighter than the enviroment (sure, it is brighter when the colors are right too, but not this much brighter).