Need HQ pictures of AV modded Famicom boards

Started by UglyJoe, May 14, 2010, 09:48:28 pm

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Don't have that one yet.  Photos would be much appreciated :yoshi:



Is the AV Famicom really worh it? I already got a Twin Famicom and i'm really tempted to trade it, or sell it for AV Famicom cause i really  hate the short controller cable :(
That Guy



Did you get the scan of the HVC-CPU-06 board?

My square button famicom stopped working today (dry solder joint on the power-jack)

First time to take apart but it has the CPU-06 board

It is different to the round famicom -06 board listed here are it has two rubber strips each side of the center chip.

Do you want any pictures of it?


Quote from: Terpor on June 06, 2012, 12:29:50 pmIs the AV Famicom really worh it? I already got a Twin Famicom and i'm really tempted to trade it, or sell it for AV Famicom cause i really  hate the short controller cable :(

Damn I have an RGB modded AV famicom, but want a Twin Famicom since I am an FDS fan, so I feel your pain! Having SNES controllers connected to my AV Famicom is sweet!


I have both a Turbo Twin and an AV Famicom and i'd never part with either. Probably need some new pads for the controllers in the Twin but its a great talking point and extremely convenient to show off Famicom games at events (cause it only needs one power supply)


December 03, 2019, 05:44:41 am #24 Last Edit: December 03, 2019, 05:58:39 am by wyatt8740
Sorry for the bump, but I don't think anyone ever posted it– my fami's an HVC-CPU-06 that I successfully AV modded. You can treat it exactly like a -07 board, though, for the purposes of the mod. Not sure if it's exactly what was asked for, though, since I replaced the whole RF modulator board on it.

I used the AV famicom diagram for the video portion, but also replaced the original power supply board. I'd recommend future modders not do that; it's more trouble than it's worth and I don't think I used a big enough heat sink.
AV mod:

Click the pics for full sizes.

I ended up adding a tiny electric fan because of the cooling problem with the FDS ram adapter attached (heat sink too small), but here's a picture of the perfboard without the fan circuitry.

There's nothing remarkable underneath since I lifted pin 21 on that console.

If you want to see one where I did, my -07 used a similar concept, but I added the video amp stuff to the original rf modulator instead of replacing it. The only difference between the -06 and -07 mainboards is the surface mounted SRAM of the -06 board. Positioning of all other parts and non-RAM-related traces is identical. I actually modded the RF modulator I desoldered from the -06 for the -07's AV mod, since I could work on that before taking out the original part, so what you're looking at is the RF modulator of a -06.
I did not lift pin 21 on this console, but I did perform a cut which is mostly obscured by the wire leading off the pin. I also did a cut to the trace leading to the destination point I soldered the other end of that wire to. The result is passing the un-amplified signal back to the RF board (where I also cut the video input line) via the original set of wires (the "ribbon").

I used a 2N3906 instead of the 2SA937 transistor on this board. It's mounted upside down for height clearance, along with two series resistors adding up to 300 ohms and the 220uF capacitor.

Used the RF switch RCA jack for video out, and the TRS jack for dual mono. Superglued it down, using hot glue blobs to hold the TRS jack in place while the superglue cured.


I hope this is helpful, despite the unorthodox steps I took in modding my -06… Sorry for the bump if not.


December 03, 2019, 08:12:19 am #25 Last Edit: January 27, 2020, 03:39:35 pm by P
I'm not sure if pictures are still wanted, but I don't know, this thread is still a sticky.
Thanks for the pictures anyway, the custom power board was fun to see. :)

I think the latest recommendations is to not lift pin 21 retaining RF output, no copper foil and put a tantalum capacitor between 4.7 to 47 µF on PPU pin 20 and 22 (which is RESET, but also +5V on Famicom since Famicom never resets the PPU unlike NES). I'm not entirely sure though.

This AV-mod circuit seems to be the result of the latest research:

PPU.20 ----------------+---------------------------------+--------+
 |                     |                                 |        |  Ring
 |                  | / (c)  2SA937               560pF ---       +----O } Composite
 |         PPU.21 --|< PNP                      Ceramic ---              }   Video
 |                  | ^ (e)      220uF                   |        +----O }
--- 4.7-47uF           |     Electrolytic     110        |        |   Pin
--- Tantalum           +----------|(---------/\/\/-------+--------+
 |+                    |        +
 |   (+5V)     300     |
PPU.22 -------/\/\/----+

According to that thread it's basically the AV Famicom's circuit, plus a tantalum capacitor (anything from 4.7 to 47 µF) between the PPU's +5V and GND, minus a ferrite bead and minus a 560 pF capacitor. Tantalum needs to be soldered directly between PPU pin 20 and 22 to filter the noise on the PPU's power rail. No need to cut pin 21 and sacrifice RF or wrapping the PPU in copper foil.

(Caution: This circuit is for Famicom. On NES frontloaders, PPU pin 22 isn't tied to +5V but instead tied to the RESET button.)


hehe mine idea is similar :) ,but I keep all intact :) and use RF as well