Famicom + AV Mod = vertical lines?

[aclbandit]

I've heard speak of the "vertical line" problem on basically every Famicom/NES except the American-toaster model.

I just modded my Famicom successfully to output wicked AV/Stereo sound. It sounds great, and save for one issue, looks fantastic as well.

I have the "discolored vertical lines" problem. It's not too bad on stationary-screen-based games like nazo no murasamejou or zelda, but for stuff like SMB2j, it's really distracting.

The part that makes me feel a little bit better is that it does it on RF modulation too, indicating that it's not something I did wrong in my modding.

My question, of course: "Is there a way to fix this?"

I read something online about replacing a capacitor somewhere in the video circuit on the NES2 from America; would this same procedure work on the original HVC-001 Famicom, and, if so, is there a nice, well-documented tutorial on how to do so without breaking anything?

[FABombjoy]

On the US toploader, the vertical lines seem to be caused by the close proximity of the composite line to an adjacent address line.

Depending on which circuit you've used - if it's the version where you connect the new circuit directly to one of the chips - you can cut & lift the composite pin and get rid of the lines that way. This has worked for me with the toploader.

If you've used the circuit that makes connections near the RF modulator, it won't quite work that way. You *might* be able to cut / lift that pin, and connect a seperate wire to it, keeping as much of if away from the bus, and run it over to the first component that it ends up at (don't forget to cut the same trace at the component as well). I have no idea if this would work, but hey, it's free advice

[jonjandran]

I read something online about replacing a capacitor somewhere in the video circuit on the NES2 from America; would this same procedure work on the original HVC-001 Famicom, and, if so, is there a nice, well-documented tutorial on how to do so without breaking anything?

Replacing or adding capacitors never fixed the vertical stripe problem on the US toploader.

As mentioned it is an interference problem. Cutting and rerouting the composite trace should do the trick though....

[aclbandit]

Replacing or adding capacitors never fixed the vertical stripe problem on the US toploader.

As mentioned it is an interference problem. Cutting and rerouting the composite trace should do the trick though....

Augh. That doesn't sound like a good time. Mind you, this is a FAMICOM HVC-001, just to be sure we're talking about the same thing. Any good pictures and/or a tutorial for re-routing the composite trace line, or is this a "lol good luck" situation?

[FABombjoy]

You don't need no steenkin' pictures

Find the pinout for the main IC, the one that outputs the composite video, I don't remember which one it is offhand.

Disconnect & lift the pin that outputs composite video

Follow it's trace to the next component. Lift the component leg / cut the trace (if it's a junction). Solder a wire from IC to that next component. Keep the wire away from other things as much as possible.

Let us know if it works, and 'lol good luck'

[aclbandit]

You don't need no steenkin' pictures

Find the pinout for the main IC, the one that outputs the composite video, I don't remember which one it is offhand.

Disconnect & lift the pin that outputs composite video

Follow it's trace to the next component. Lift the component leg / cut the trace (if it's a junction). Solder a wire from IC to that next component. Keep the wire away from other things as much as possible.

Let us know if it works, and 'lol good luck'

AHA! Just figured out why I'm lost here. See, the reason that I "AV Modded" this here Famicom was because the original model only output RF Modulation .

This "MOD" that I did to it was to enable a composite video output. I built the circuit that does composite video. So I can't change the famicom's composite output-- It doesn't HAVE one! ^^

Okay, any other suggestions

[FABombjoy]

Let me "un-lost" you then

An RF-Modulated signal is a composite video signal re-modulated to a specific, much higher frequency used to transmit television signals.

You cannot have an RF signal without first having a composite video signal.

Ergo, you have built a circuit that takes the pre-existing composite video present within the Famicom - a signal that exists pre-modulator - and created an output for it.