I have installed the composite board from helder on this forum. I have clipped the video out pin on the PPU and run it to the video board along with the required audio, power, and ground. The video was much better than RF on my toploader, however, as I started to play games I noticed that the jailbars that were so prevalent were still there on lighter backgrounds. Anything with a light blue, grey, or white seemed to show particularly bad. From my reading, it seems that this can be overcome in two ways, get a shielded cable for the composite wire going to the back of the system (I read that Ethernet cable wiring was good for this), or wrap this cable with another cable that is soldered to ground. Has anyone used either of the two methods listed? If so what worked for you?
Of course you still have jailbars ;p You will need to do a lot of stuff to get the picture cleaned up. Much more capacitance on the IC power supplies is the biggest help. Full shielding of the PPU is next. Shielded cables to your mod board and if the board is close to other IC's, shielding for it as well. Getting rid of all the jailbars in old consoles is difficult. Use this as a guide: http://jpx72.detailne.sk/modd_files/fc/avmod.htm
Wrapping the ppu in copper film and attatching that to ground will clean a lot of that up (enough in most cases). Just dont short any pins together when wrapping.
@GoodTofuFriday have you combined PPU wrapping with additional filter caps and checked the result on a tft screen? I worked on a Famicom for a while and managed to reduce the jailbars, but I never fully got rid of them. On a crt tv, they're almost completely gone but on a flat screen, you can still easily make them out.
This is on a CRT, and I am not seeking perfection, just a reduction to where it is not evident in normal operation.
GoodTofu's method is what I use and it helps alot also changing the regulator to a modern switching regulator with filter caps should help also.
Have you had success wrapping the PPU without desoldering it? As far as filter caps, you are describing the cap added to the power legs of the PPU described in the link?
Yes and its why I suggest copper foil over tape. You make a long thin strip to wrap around the ppu by slipping it under. Where the beging and end of slip meets you solder it together along with a wire. Then attach the wire to ground. Maybe put glue or something to keep it from sliding around. As for a cap on the power pins you can do it but I don't think it's needed if you aren't trying to get it perfect. It just makes thing complicated.
You can try adding a cap to the cpu as well, some people had success with that. Also try what helder suggested in this thread.
SMD ceramic capacitors work really well in Famicom / NES consoles. It's actually the most simple way to get a cleaner picture. Just place 2 or 3 of them where the original caps are, preferably around 1uF and close to the PPU.
So, not having any electronic components around, I replaced the composite wire with a shielded wire from an RCA cable and soldered the shielding to ground on pin 20. It cleared up almost all the jailbar effect. I don't have any perceivable effect on the blue in SMB and can only barely see it in the light grey color on Jackel. So I think for now I will call it fixed.
I've read Console5's version works pretty well according to MaxWar. http://console5.com/wiki/File:NES_Toploader_AV_Schematic.png