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Non-NEC Console Related Discussion => Console Chat => Topic started by: ProfessorProfessorson on July 20, 2015, 12:30:19 PM
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I know there are slightly different revisions of the system and all, but what I have read is that the mod is essentially the same. But the guides I keep coming across vary in methods and resistor values and what not. Is there any really solid well put together guides out there for this with a correct parts list?
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I would be interested in this as well. I have seen so many different values and tweaks on the method, I do not know which is the best.
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No dice ehh?
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The issue is Famicom (and NES) can only do composite without replacing the PPU. And composite is fairly simple, usually a single transistor and 2 resistors plus a cap for audio is all one needs. The value seems to vary but that's mainly because not everything is exactly the same (even the TV can vary), one would still need to adjust resistor for best value. What one could do is grab a basic 50k variable resistor and use that between video source and transistor base then adjust it til the picture looks best. Then measure the resistance of the variable resistor and find a fixed value resistor of the closest standard value to use.
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I have never done one personally but I know the Famicom guys have big time problems with jailbars. So bad that some of them have desoldered the PPU and insulated with gold foil and re-installed. In my opinion, if you went that far, you might as well do the RGB mod.
jperryss on these forums had me repair a top loader NES (similar in layout to the OG Famicom and obviously nearly identical to the A/V Famicom) and he had a composite mod installed that really had a great picture with no jail bars. I suggest trying to contact him and find out who performed the mod and then you might be able to find the circuit design behind it.
Actually here's the link. You can see the home made board in one of the "fixed" pictures. https://www.pcenginefx.com/forums/index.php?topic=17121.msg354215#msg354215
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It's a little expensive but the NES RGB kit is amazing. The picture quality is so awesome and it gives you options to use composite and SVID as well. Another awesome feature for original famicom is it has a built in simulated stereo with channel adjustment. I highly recommend it.
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It's a little expensive but the NES RGB kit is amazing. The picture quality is so awesome and it gives you options to use composite and SVID as well.
100% agreed! Love my RGB NES!
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Yeah I just wanna do a composite AV mod. Nothing fancy. I plan to run the thing into my iScan. I have a Famicom on the way. When it arrives, given it test ok, I will clean it up and refub the game pads and see what revision it is. Then I can work on modding it, see what mod I will need. I gather this mod involves tapping one of the ppu pins?
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I've heard these pre-made boards are decent http://www.otakus-store.net/en/content/12-famicom-av-kit
Console5 also has a good setup if you're building your own. http://console5.com/wiki/Nintendo_NES-101
I will stand by my statement that the A/V mod in jperryss top loader had the cleanest picture I had ever seen with the A/V mod.
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Oh yeah the PPU signal jail bar fix people were doing with copper tape made me think of something. I think I have a easier way to do that with aluminum. Basically take a long thin strip of aluminum or copper tape just almost as wide as the ppu. Cover both sides of the strip in one layer of clear tape to prevent it from touching multiple pins from the ppu, and slide one half of the strip under the ppu, and work the other half over it, overlapping the strip some and just tape the overlap together.
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Oh yeah the PPU signal jail bar fix people were doing with copper tape made me think of something. I think I have a easier way to do that with aluminum. Basically take a long thin strip of aluminum or copper tape just almost as wide as the ppu. Cover both sides of the strip in one layer of clear tape to prevent it from touching multiple pins from the ppu, and slide one half of the strip under the ppu, and work the other half over it, overlapping the strip some and just tape the overlap together.
Yeah that's good thinking.... I would probably ground your "shield out too so plan for a way to work that it.
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Doesn't the Famicom 2 have a A/V without modding?
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Prof, which mod did you end up using?
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Prof, which mod did you end up using?
He is using RF on a b/w TV.
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Prof, which mod did you end up using?
He is using RF on a b/w TV.
No, RF on a b/w TV is the only way to make OBEY look worse than NES/Fami :P
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Prof, which mod did you end up using?
I ended up going with the tiny av mod kit from Console5 that was a few bucks. I cut the ppu pin and soldered to it, and also added two 470uf caps at the bottom of the main pcb in different spots to help reduce the vertical lines. I got them down quite a bit compared to what some people have had after doing the mod, so I am not sure I will bother with shielding the PPU at this point. Also, I replaced the 1000uf cap. The old one was probably fine still, but better safe then sorry.
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Prof, which mod did you end up using?
I ended up going with the tiny av mod kit from Console5 that was a few bucks. I cut the ppu pin and soldered to it, and also added two 470uf caps at the bottom of the main pcb in different spots to help reduce the vertical lines. I got them down quite a bit compared to what some people have had after doing the mod, so I am not sure I will bother with shielding the PPU at this point. Also, I replaced the 1000uf cap. The old one was probably fine still, but better safe then sorry.
Thanks for the info! I've got an extra fami in a box somewhere I'd like to put a composite mod on as well, sounds like you had good success with this iteration of the mod.
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Yeah it went fine all in all. I suggest while you are in there to just go ahead and at least swap out the 1000uf 6.3v cap if nothing else too. You can do the few other small ones also if you'd like, but that is the main one you'd want to swap out at this point.
There is a guide on a link I am posting. It will show you where to solder the extra caps on the bottom of the PCB to help reduce the jailbars even more too:
http://www.otakus-store.net/en/content/12-famicom-av-kit
Just scroll to the very bottom of the page to see where they put them on the two different revisions of the Famicom. I used 470uf caps when I did it. Also, keep in mind that the Console 5 kit, the cheap one, he does not label the values of the resistors, so you will need to use a color chart to figure out which one is which when they arrive.