No sound from my Famicom

[toploaderleo]

I just got a beautiful Famicom in the mail today and it powers up. I hooked it up to my television with the NES RF switch. I'm getting fantastic video but no audio. My tv is set to channel 95 and also works on 96. Ive tried other channels and changing the famicom's channel setting. I still have the same problem.

[SPAZ-12]

I seem to recall that the NTSC-J specs have the audio and video channels separated more or less than standard NTSC. That would mean that the video appears on one channel on your TV, and the audio on another.

If this is the problem, then you would probably need two different channel decoders. For instance, put a splitter on the RF switch, tune the TV so that it gets video, and use a VCR tuned to the correct channel to output audio, perhaps to a stereo receiver.

[toploaderleo]

hmm, your the first person to say to use it through the VCR, Im going to give this a shot. Cause I tried to adjust the audio on my television, but it has no such feature.

[FABombjoy]

If these sources are accurate:
https://en.wikipedia.org/wiki/Television_channel_frequencies#Japan
https://en.wikipedia.org/wiki/North_American_cable_television_frequencies#North_ America_cable_television_frequencies

...A Famicom set to channel 1 will appear on US CATV channel 95, with a 100% match on both video and audio carriers. Is it a genuine Japanese-market Famicom, not a clone or from a different region?

I'd try it on a different TV first, and then test the audio output on the CPU and go from there.

[toploaderleo]

Yea its a legit Fami, and I know I should get it on channel 95 & I get a pic but no audio Ive been told to fiddle with the fine tuning but that proove to no a vale. So now Im going to hook up my Fami to my VCR & hook the VCR up with AV jacks as a posed to a coaxial. this may work I think. :/

[toploaderleo]

Ok so I hooked it up to the VCR liek I said I would. Nuting. I tried hookign it up to a different TV & on channel 8 I got the opposite, no video and only audio.

[jb143]

I think the idea was to split the signal to a TV and a VCR. Have the TV on 95 and the VCR on 8 then run the audio output from the VCR to a stereo system.

I had no idea there was that much difference in the A/V separation between US and Japan.

Edit:
Hmmm...according to the frequency tables linked to above, the audio and video signals for Japan channel 1 do exactly match US channel 95 (Video=91.25MHz, Audio = 95.75MHz). Channel 8's audio is 185.75MHz which is closer to the 2nd harmonic of the audio signal(191.5MHz). Interesting. Why does it not just get audio on channel 95?

Is it possible someone messed with the tuning in the Famicom? I know with some equipment it's possible to "walk" the signal by adjusting components. Sometimes as simple as slightly moving the wires on a coil.

[FABombjoy]

There shouldn't be that much separation, see the links I posted above. Seems like the modulator is out of adjustment or defective.

Edit: You're a ninja!

[jb143]

Yeah, that's probably a better explanation. Something in the modulator is likely out of whack. Still, would it be possible to tune it back to the correct frequency? I'm not too familiar with the Famicom's inner workings.

[FABombjoy]

I just made a quick check on a parts system: There are 4 coils and 1 variable cap that can be adjusted. There is a Famicom schematic floating around but I dont recall if the modulator is detailed in them. I would probably just install an A/V mod kit and call it a day :)

[APE992]

My 2 cents:

I didn't know the Famicom even separated audio/video in such a fashion as discussed above, but here is what I know:

When my toaster NES, after many years of faithful service, stopped putting out audio I was confused. Maxed out my stereo and I could hear it again! But obviously that wasn't a valid solution unless I wanted to potentially blow something expensive.

The solution? Replace every capacitor on the small daughterboard for Audio/Video output and power input. Sound came back 100% and I only needed to run my stereo at 1/10th the level. After 25 years I wouldn't be shocked if your Famicom's capacitors haven't dried up. I can't say this is a sure fire fix but it is definitely worth considering given how cheap it is to replace a handful of capacitors ($2-3).

[toploaderleo]

I know the famicom does make noise so the Fami's hardware is fine. It's juist not compatible with any of my televisions. SO Im going to buy the AV kit soon :/

[FABombjoy]

I didn't know the Famicom even separated audio/video in such a fashion as discussed above
Anything that outputs RF does. Roughly, you take this:
https://en.wikipedia.org/wiki/File:Ntsc_channel.svg
And now modulate that information on top of a VHF, UHF, or other radio wave and you have RF broadcast video.


The solution? Replace every capacitor on the small daughterboard for Audio/Video output and power input. Sound came back 100% and I only needed to run my stereo at 1/10th the level. After 25 years I wouldn't be shocked if your Famicom's capacitors haven't dried up.
I've had similar experiences with the toaster with 60hz audio buzz and video hum bars and won't sell a NES that I haven't put one of my cap kits in. There's a lot of heat in that little RF/rectifier box, a surprising number of caps crammed in there, and the caps are usually stretched out and spent, sending AC ripple throughout the NES and setting up the potential for IC failure.


I know the famicom does make noise so the Fami's hardware is fine. It's juist not compatible with any of my televisions. SO Im going to buy the AV kit soon :/

I agree that if you can hear audio on a separate channel, then the audio circuit is more than likely fine. If you're considering A/V modding anyway, you can always twiddle the adjustments on the modulator. Can't do much harm now, really.

I'd turn to 95 and start messing with that variable cap. Likewise, if any of the red/green coils look like they've been messed with, squish them back together. Those were originally tuned literally by knifing them apart until the frequencies were correct, so knife away and see what you end up with. Maybe take a few pics so you can return it to stock, if you're so inclined.

[toploaderleo]

Bought the AV converter. Looks like Im modding it -_-

[APE992]

I've had similar experiences with the toaster with 60hz audio buzz and video hum bars and won't sell a NES that I haven't put one of my cap kits in. There's a lot of heat in that little RF/rectifier box, a surprising number of caps crammed in there, and the caps are usually stretched out and spent, sending AC ripple throughout the NES and setting up the potential for IC failure.

Never seen hum bars on a NES but I have on several TG16s. Did replace every capacitor in there but I'm guessing ground loop (very possible but damn the engineers must've been lazy) or another part I've yet to consider at fault. Even ran it off a battery to eliminate its own power supply as a possible fault, or my electrical wiring.

Still not sure why Nintendo went with a power supply that just dropped the voltage of incoming AC. Then again the Japanese may have had different ideas about how to engineer power supplies for consumer electronics. Though as a result plenty of SegaCDs have been fried by people not really looking too closely. *COUGH*

[FABombjoy]

Bought the AV converter. Looks like Im modding it -_-
Out of curiosity, where did you pick it up?

[jb143]

I'd turn to 95 and start messing with that variable cap. Likewise, if any of the red/green coils look like they've been messed with, squish them back together. Those were originally tuned literally by knifing them apart until the frequencies were correct, so knife away and see what you end up with. Maybe take a few pics so you can return it to stock, if you're so inclined.

Probably better to start on channel 8. Make adjustments to coils and such(using something non-metallic) until the audio shifts to channel 7 or 9. This is what's known as "walking" the signal. If you keep at it, you should be able to match the audio to the same channel that video is on. Keep in kind that the TV bands jump around. For example, if you walk the signal from 8 to 7, after 7 it should jump to 22. Then it will go 21, 20... down to 14 but then jump to channel 99. From there you should be able to walk it down to 95. Look at the link FABombjoy gave above and you should see what I mean.

Since the coils and variable caps are exposed it actually wouldn't be too hard to do. Just don't mess with anything that affects the video. And if it does, fix it and remember not to touch that component anymore.

[toploaderleo]

I got it from http://atariusa.com/RetroVideo/ about a week and a half ago. I paid for 2 to 7 day shipping and havnt recived it yet, so Im not about to recomend this guy t anyone anytime soon. Also Emailed them and havnt heard from them either.

[FABombjoy]

If you end up not getting it from them, I have a parts kit available for $3, small perfboards for $.79, jacks, etc., plus I ship first class. It's a super easy circuit to build.

[toploaderleo]

Ill keep ya in mind. First I want to get my money back from him or at least know whats going on with my order.

[ApolloBoy]

Ill keep ya in mind. First I want to get my money back from him or at least know whats going on with my order.
I know the guy who created the RetroVideo, he hasn't been online in a few days. As I understand he's been having health issues lately so I wouldn't be surprised if that's what's keeping him offline.

[toploaderleo]

Yea it was bad timing on mmy part and bad luck on his. Ya see he was at a convention when I ordered them then when he got back something happened where he couldnt contact me for 2 weeks, so with a month of silence & no way of knowing what was going on. I lost hope & went a different direction. I have modded it myself by now. But I wouldve much rather used his. because of how much simpliar it was.