Technical and Repair Assistance

[nintendodork]

Could be the pin connector and/or the games if it's not a problem with your TV.  Make sure all of your games are clean, as well as the Famicom's pin connector.

[knux123]

I don't know, the image seems like "it's too big", if you see the photo
The other TVs have the same problems, but display the colors correctly.
UPDATE: I cleaned the connector and the games, but it still gives me problems.
Also, every game reacts differently. It doesn't stay like this the whole time. In Excitebike, the menu works fine, but when the demo starts the image becomes like this. Selection A sometimes shows the messed up image, sometimes not. Finally, when I move around the video cable sometimes it actually misadjust the image like in the photo. 
Post Merge: July 30, 2010, 06:48:51 am
Anyone?

[cubelmariomadness]

You could go into your display settings and move the picture up maybe?
Also, the av mod could be improperly done.

[knux123]

Maybe that's the case because I also see lines across the screen, even if they are really thin.
EDIT: referring to the av mod being improperly done.
EDIT 2: Yet another update: I tried the console on my HDTV and none of my games have this problem, BUT when I tried Mario 3 (which now I don't have anymore) on the same tv it had the same problems.
Strange, Excitebike works just fine on the tv, I tried every mode.
EDIT 3: Last edit I swear!
I believe I found the culprit. Testing the console again, with other cables, I've reached the conclusion that there is something wrong with the av jacks. I don't know if the problem are the av jacks themselves or it's the connection between the jacks and the board.

[weedkiller87]

I have a 1989 Famicom model (blue/silver connector), with an official Famicom AC adapter.  It is hooked up to my TV with the official Nintendo RF adapter.  I am very happy with the system and I am enjoying it very much.  However, I am having a problem.  On certain screens/levels in some games, I hear a static noise in the background, but the video quality looks fine.  For example, in Zelda no Densetsu 1 (cart version), the first screen you start on after selecting a file, has a lot of static noise.  However, a couple screens later, the noise is gone, and you can hear the game music perfectly.  Also, in Akumajou Densetsu, there is a lot of this noise on the title screen, the name entry screen, and in some of the later levels (e.g., Block 7).

I have played my Famicom on an HDTV and an old tube TV, and it happens on both TVs.  I have also played NES games and on my Famicom and there is a little static too.  What could be causing this?  Is this just interference, a bad RF switch, or something else?  I hope my Famicom is not damaged. 

When I get the chance, I will try doing these things to attempt to pinpoint the problem:
1) using an RF plug/adapter and a coaxial cable on my Famicom
2) using my RF adapter with my NES
3) using a brand new RF adapter with both systems

Has anyone else experienced this problem?  If so, what was the cause?  Please let me know what you think and any other suggestions you might have.  Thanks!

[ericj]

Have you tried adjusting/moving the microphone volume on controller #2 when this happens to see if that makes it go away?

[weedkiller87]

Yeah, I noticed that the microphone switch does cause noise sometimes.  I feel the problem is something else though.

[cubelmariomadness]

Same problem I have with my power joy.

[ericj]

May also be the filter capacitor is wearing out. When there is extra current draw, it may inject some interference by not smoothing out the current as well, but I'm not sure. You could also try cleaning the cart connector.

Maybe 133MHz has some ideas.

[weedkiller87]

Do you think I would need a step-down transformer?

[133MHz]

Sounds like the video signal is interfering with the audio signal inside the system. Depending on the picture content, the kind and amount of noise will vary. In your case it seems that screens with a lot of black content produce the most noise (title and file selection screens). Assuming the RF adapter and the TVs are fine, there are two probable causes for this problem:

• Faulty AC adapter that's putting out an excessively noisy DC output, causing the video modulation stage to go bonkers. Try another Famicom compatible AC adapter and see if the problem goes away (do not use the NES one!)


• Sound carrier frequency drift (also known as Sound IF). The RF modulator mixes the sound with the picture content in a precise point of the broadcast TV channel, this point is adjustable by means of a variable inductor can that can be tweaked with a small, plastic screwdriver. If the sound IF goes out of alignment, you'll get anything ranging from distortion to complete loss of audio. In this case it seems that it has gone a little out of tune, producing interference with the video carrier.

Don't touch the frequency adjustments until you've exhausted every other possibility, or you'll make the problem even worse. To align the sound carrier on your modulator, you'll need a jeweler's screwdriver that's completely made out of plastic. This is a specialized tool for tuning modulators, a metal tool will provide nothing but frustration because these circuits are so sensitive that even putting your hand near them will mess up the alignment.

The alignment needs to be done by ear. Hook up your bare Famicom to the TV, put in a game and set it on a "noisy" screen. Then start tweaking the sound coil on the RF modulator board by rotating the adjustment screw with the plastic bit until the audio comes loud, clear and free of any distortion.

If you provide a clear picture of your bare RF modulator board, I can point out which is the sound carrier adjustment coil.

[weedkiller87]

I'm not that good with electronics so I'm going to try anything complicated.  If I come across another compatible Famicom adapter, I will try that.

[knux123]

Can anybody confirm if I'm right?

[133MHz]

It won't work. The ZVN2106A is a FET, or Field Effect Transistor, while the 2SC1815 used for the Famicom mod is a bipolar junction transistor.

[xyzzy32]

My FDS works fine for all my disks except VS Excitebike. The title screen, track / disk editing mode, and VS mode all load smoothly, but if I choose the 1-Player "Original Excite" game, the drive fails 85% of the time when attempting to read Side B. At the "Set disk to Side B" prompt, after I insert the proper side, the drive usually tries to read the disk for several seconds, stops, resumes loading, and then crashes a few seconds after- leaving me with a scrambled screen and a sustained chord, a bit like what you hear when your computer freezes while a sound is playing.

On occasion, the game loads without a hitch, and doesn't stop in the middle of loading as it does when it fails. I've also noticed that the drive has begun to fail much more than it used to. What could possibly be the cause of this all?