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 :D

[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.... :hmm:

[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.... :hmm:

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.

[aclbandit]

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.

FANTASTIC! Now where do they keep that composite line? Is it in the RF "metal box thingy"? or is it somewhere on the main MoBo?

[FABombjoy]

Pin 21 of the PPU (RP2C02G)

[aclbandit]

Pin 21 of the PPU (RP2C02G)

Okay, looked up what a PPU is (sorry, I'm kind of a nub at console modification) and now know what to look for.

The only remaining problems, of course, include two things:
1) Is the PPU made the same way in the Famicom, and will pin 21 "bending" be the same pin as in the NES?
Also,
2) How do I figure out which one is #21?

[theChad]

The #1 pin will be marked by a little notch on the chip (whichever corner it starts in) and you just count up from there. When you get to the end of one side of the chip, the count continues directly across from the last pin on the first edge.

[aclbandit]

The #1 pin will be marked by a little notch on the chip (whichever corner it starts in) and you just count up from there. When you get to the end of one side of the chip, the count continues directly across from the last pin on the first edge.

Aha, thank you! I'll look into doing this once I buy some more solder. Worst case, I just solder it all back the way it was, right ^^?

[ApolloBoy]

1) Is the PPU made the same way in the Famicom, and will pin 21 "bending" be the same pin as in the NES?

Both the NES and the Famicom use the same PPU. There aren't really a whole lot of differences between the two, with the exceptions of different form factors and different cart pinouts.

[aclbandit]

I rolled that pin-21-to-next thing. It still looks precisely the same as it did before. Perhaps a little sharper picture, but the vertical lines are still evident.

Any more tips?

[Cornelius]

did you cut the line that you replace with the wire?

[aclbandit]

did you cut the line that you replace with the wire?

if by that you mean "did you lift pin 21 so that it touches nothing but your new wire", then yes, I did that. Otherwise, elaborate please ^^

[Mitch]

if by that you mean "did you lift pin 21 so that it touches nothing but your new wire", then yes, I did that. Otherwise, elaborate please ^^

Did you use a shielded wire? I noticed a difference using a shielded wire over unshielded.

Mitch

[aclbandit]

Did you use a shielded wire? I noticed a difference using a shielded wire over unshielded.

Mitch

I used speaker wire, lol. It's got that plastic-y casing over it. But after that, it really doesn't look much better, and the lines are certainly still there.

[aclbandit]

*bump* Still looking for tips on getting rid of those obnoxious vertical lines. They're not missing pixels, they're simply discolored so as to be much lighter than the pixels should be, but only on that line every 10 pixels or so.

Help is appreciated.

[Mitch]

I used speaker wire, lol. It's got that plastic-y casing over it. But after that, it really doesn't look much better, and the lines are certainly still there.

That's not shielded. It should have a wire braid inside the outer plastic. You would also need to connect both ends of the shield to ground. That will probably fix your issue.

Mitch

[aclbandit]

That's not shielded. It should have a wire braid inside the outer plastic. You would also need to connect both ends of the shield to ground. That will probably fix your issue.

Mitch

Aha, I'll check it out. Thanks again.

[aclbandit]

I just came to the realization that this might be my VCR or Composite switch causing the lines, as they were there on the VCR's blue screen of "nothing turned on now." Which would explain why nothing fixed it.

The inability to test it elsewhere comes in the fact that the transistor seems to be so strong that the video "explodes" if plugged straight into the TV or Composite switch.

Suggestions?

[aclbandit]

By way of an update, I discovered that the vertical lines are ONLY present on my famicom and my Channel F; otherwise, they are not. This indicates that it's simply something up inside old consoles that makes it do that nonsense.

Apparently, the US toploader has the same exact problem. I guess I'll just live with it, since my only other option is to pick up one of the third-party Famicoms that don't have the 2nd player microphone with which to yell at bunnies in Zelda. And I like yelling at bunnies.

[Mason P.]

i wanted to see how this story ended.

[JBK Games]

I have read a number of posts which say the only way to fix or minimize the vertical line problem on Famicom top loaders is to do some heavy duty board cutting, soldering, jumper rerouting, etcetera.

I just wanted to share that I found a simple way to reduce the lines. I went in and cleaned up the board with a little alcohol and an air gun, then I used this overcoat acrylic conformal coating pen to reduce the noise going on. Covered parts of the board where it is believed to be the problem.

This stuff can also be removed really easy with a Q tip and some alcohol, or with a plastic shortened dull toothpick, if you decide you want to remove it. It also protects the board from moisture, corrosion, arcing, static discharge, etc.

Also I messed with the RF mod unit video inductor coil which seemed to improve the image a bit. Right now it's hooked up and drying for a minute, but the lines seem to be fading even more as the conformal coating drys and evens out.

All dried out now, check out the difference with before and after photos as attachments below.

:eek:
Anyway, if anyone has any success with this method or any cautions against it, lemme know. I'm a long time vintage retro gamer, and collector, but just getting into the forums.

[FABombjoy]

You could also use the lineless mod for toploaders. I've used it and the image is perfect.

[The Manimal]

You could also use the lineless mod for toploaders. I've used it and the image is perfect.

When did this fix come about? I remember no solution being out there for a long time - people trying to shield various things to no success. I was going to do an A/V mod for the top loader but figured it would be a waste of time if the lines were still there.


Is there anyone out there that does this mod for a fee?

[FABombjoy]

I just reread my reply and it might be a tad misleading.

I've used the lineless mod on toploader NES units. Since both the Famicom & toploader exhibit the same symptoms with that style of mod, I have to believe the same (very simple) circuit could be used in the Famicom with good results.

The lineless mod has been described here before, and I think the original design was posted on nesdev.