Famicom A/V Mod...

Sometimes, I hate the internet. There are so many different schematics all saying that "this is the proper way to do it".

I've already done the AV mod to a NES Top Loader that works just fine. I should just be able to apply the same mod to the Famicom, right? Anyone here AV modded a Fami? Please help.

I've done both the NES toploader and the Famicom mod, and the mod isn't exactly the same. It will work, but the amp that looks so great on the NES doesn't look so hot on the Famicom.

The Famicom's biggest problem is interference on the inside, causing jailbars. Some people live with it, some do not. I don't remember exactly what schematic I used, but head over to Famicomworld, there is are a few big thread about it (I'm even in a few of them) and listen to 80sfreak, he knows his shit more than anyone although he comes off a bit cross at times.

My personal method to get the best AV possible was to build the composite video circuit, lift the composite video pin from the PCB (debatable if that does anything, but I did it anyway,) shielded the PPU (the source of the interference) and even ran some aluminum foil along the AV wires on the inside of the system for some extra shielding.

I'm so-so about the whole jailbars thing. My top loader does that. I've tried the "cap across /SYNC and GND" tonight with 2 different caps and they didn't do a thing.

GohanX: Do you have an idea on how I can just remove the RF modulator off of the Fami? If anything, would you know how to recreate the power circuit?

hey have a look at the forums over at http://famicomworld.com/, they have a stickied topic on the a/v mod + jailbars and its been whittled down to quite a nice solution over the years...

I did. I read all the threads up and down. The one mod one of the forum members said "this is the 'best and only' solution" gave me bad jailbars worse than my TL NES. I may try the Pin 21 isolation thing to see if that works.

perhaps try this one, http://www.boards.ie/vbulletin/showthread.php?p=82882662 on my two famicoms (one japanese and one hongkong official unit) I had to experiment with the cap across pins to nuke the jailbars totally... also experiment with the little switch on the back of yours if it is there as this is sometimes used to go between a pal50 and ntsc60 output speed - might make a diff on your tv - you'll be able to hear the difference in the music...

I'll give it a shot. I tried doing this method on my TL NES (used a 47uF and 100uF cap across 20 and 22), but neither worked.

On 80's Freak's mod, instead of 33uF cap I used a 100uF cap, resulting in not much difference, so I left the 100uF in. I'm gonna up the cap across 20 and 22. Suggested was 0.1uF cap, but that doesn't do crap.

Thanks for that link, ne7. Came in handy.

goombakid said:

GohanX: Do you have an idea on how I can just remove the RF modulator off of the Fami? If anything, would you know how to recreate the power circuit?

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You can, although it's a bit of a pain in the ass, at least it was to me. I forget exactly what I did to recreate the power circuit, but it was basically just using a piece of breadboard with a power regulator (I used one stolen from a parts Genesis, it's the same as the fami) some capacitors and an inline fuse.

Sorry I'm not more help, my memory isn't so hot and I didn't type up any notes for this when I did it. I actually need to fix my Famicom since I accidentally broke some plastic off of the DC connector so the power connection is super flaky. I'm debating between salvaging a part from a junk Fami or just using a jack from Radio Shack.

I've seen a jack similar to the Fami one (same tip size and all) at Fry's around here. Otherwise, a panel mount jack would work (that's the route I was gonna take). FYI, inner diameter for the jack should be 2.1mm, outer is 5.5mm.

In the end, I just started taking out parts from the RF modulator (since I didn't care about it anymore). I broke off the original RF RCA connector and used a gold panel mount RCA jack, removed the channel selector switch and replaced it with a panel mount 3.5mm phono jack for sound.



I did something similar to my TL NES.

Nice work! I've got a panel mount RCA jack in the same spot as yours, with plans to drill out the switches into round holes for the audio jacks, but I got lazy and just ran a set of RCA cables out of the channel select holes.

GohanX said:

Nice work! I've got a panel mount RCA jack in the same spot as yours, with plans to drill out the switches into round holes for the audio jacks, but I got lazy and just ran a set of RCA cables out of the channel select holes.

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Thanks, GohanX! I did see your post about lifting pin 21 in that Famicom World thread. I was gonna go and try and remove the PPU, but I got lazy.

So, I went back in and changed (rather, added) to the capacitor across 20 and 22 from just .1uF to 32.1uf (I had a 10uF and 12uF and added that to the .1uF already installed). Tested, the lines were a little less pronounced than with just the .1uF cap. I upped it to 47.1uF (just a 47uF cap added to the .1uF), and the lines were even fainter.

Ninja Ryukenden's start screen was just riddled with jail bars before. Now, it's not as pronounced. They're still there, but not to a point where it drives me nuts.

Thanks to everyone who chimed in. I'm happy now.