Blurry, streaking RGB from PC Engine Duo (fagin amp)

[naiaru]

So I've been trying to RGB mod my PC Engine Duo. I previously replaced all the caps and composite video worked fine before and after. For the mod, I'm using the original 5 pin DIN socket and just replacing the 5v, right and left pins with red, green and blue (I'm rewiring the headphone jack to not use the amp and am using that for audio). The amp I'm using is the one posted by fagin. The DIN Ground pin is connected to pins 5, 9, 13 and 18 on the SCART end. Red to 15, Green to 11, Blue to 7, and original Composite video to 20 (original as in I can still hook up composite video cables and use that). My multimeter shows less than 2 Ohms between each of the outputs on the amp to the pins on the SCART end of the cable when plugged in and the red, green and blue wires from the chip to the amp seem to be properly connected as my multimeter says each wire is shorted to the bottom of each of the respective pads (I soldered to the top of the pin next to the chip) indicating they're properly soldered on and there's no difference in resistance between the three on either end of the amp. The wires I'm using are the same size as the ones used to connect the CD drive to the motherboard. I have the SCART cable hooked up to a sync strike that then goes to an iScan HD (output framerate is unlocked, though I've tried it locked to 60 Hz as well). I have other consoles going through this set-up so I'd think it should be fine.

Finally, the problem: I'm getting massive streaking to the right side of the screen (image doesn't quite do it justice):


My idea is that since the chip is on the bottom of the board near the front, I ended up using maybe a foot and a half of wire for each connection counting from the chip to the amp and then from the amp to the plug. Could that foot or so difference in wire be causing that much of a delay and all that streaking? EDIT: Nevermind, I added a foot and a half of wire to composite on the SCART end and that did nothing.

Here's the diagram, BTW (the only difference is that I used two 75 ohm resistors each instead of one 150 Ohm, not that that should make a difference? meter says it's fine)

(I used the 5v the A/V plug used to be connected to for the transistors)

thanks in advance for any help

EDIT: I tried replacing composite video with composite sync (I made another amp for it too), but it's the absolute same. I'll add though that when I was messing around with the cable I accidently grounded composite (when it was still composite video not sync) and that made the streaking go away but I could no longer see anything white (the streaking efect is all white).

Also, why am I splitting the output between a 150 Ohm connection to ground and the actual output going through a 47uf capacitor? What would happen if I didn't have that connection to ground? The mmmonkey guide uses transistors but doesn't split the output to ground (nor does it have the 47uf cap) which is what is making me curious.

EDIT: Okay, so I tried cutting the line to ground and at first I got a somewhat blurry but tolerable image without the streaking and just as bright as before, but then it got darker and darker every time I turned it on and off and now it's so dark I cant' see the C and M on the title screen.


EDIT: So I switched to the THS7314 amp and switched back to composite video and at first hooked it up just like the N64 (which did work with the n64) and I got a black screen, then I saw this post on another forum that said to also ground each color line with 1k resistor and have a 5k resistor with a .1uf cap at the end to the amp, that gave me no signal on rgb or composite even. I'm ordering some C1815 GR transistors to just do the mmmonkey mod. I heard people saying to not do it because the voltage is too high or something but that doesn't sound very concrete. I guess I'll find out though.
Also, I also replaced the 10uf cap at c961 with a 100uf cap as I read on another thread that it can help video quality. I haven't noticed anything, but it still works at least.

EDIT (12/24/14): I tried the mmmonkey mod and it smears slightly less than fagin's amp, but it stilll smears plenty to make it uncomfortable. White text on the composite output is pristine but blurry with RGB. I also tried all different combinations of grounding the outputs with a variety of resistors and the best I could do was slightly offset green to make it slightly sharper but add a very slight green smear. I'm beginning to think (good) RGB is simply impossible for the Duo (or at least for this unit).

[hoshikawa]

I know this thread is old but I had the same issue and I managed to fix it, the problem is the ground pin on the DIN cable is not a true ground, it has an isolation transformer between the DIN and real ground. in order to fix it you must remove the inductor coil and bridge the two grounds together. I can provide pics if anyone is interested.