RF Switch

[security16]

hmmm perhaps my problem is i'm not in the US i'm in Australia with a PAL tv but it seems to play the  japanese superfamicom on the tv without any troubles and it's not possible to try it on another tv cause i only have the one maybe i just bought a dud one

[133MHz]

Dude you are waaaay off. How do you plug yor SFC to your TV ? If you use composite video maybe that's why it works, some PAL TVs are multisystem, they are capable of displaying NTSC signals but usually only if they come through the composite inputs, not antenna. I recommend doing a temporary AV mod on the Famicom to see if it outputs any video, so you can know if the Famicom is good or not, then troubleshoot the TV issues.

[security16]

I use the NES RF adapter from the teev to the superfamicom and my NES and it works fine with those my famicom just won't play though it just sits there with a boring grey screen

[madman]

Even if his TV wouldn't display NTSC properly, he'd get some kind of scrolling picture on his screen, not just a blank screen.  Sounds like a problem w/the Famicom to me.

[security16]

   broken famicom make this girl sad
can anyone shed some light on what the problem could be ?

[133MHz]

No power to CPU board maybe. Check if +5V is reaching the CPU board first (test the output of the 7805 regulator along its path).
Then proceed to troubleshoot individual sections.

[security16]

Power is going through at the correct voltages and all of it seems fine but there is this little green bit that doesn't seem to have any power going through it ans i suspect it might be stuffed i have taken some piccies of the guts of my famicom
here is a full view of the mainboard
a closer look at the mainboard
and a closer look at the suspected problem green thingy

if the quality of the pics is not great please excuse my drunken photography  if you need more pics to help me out i can take more cause any help is greatly appreciated 
i shall go into an alcohol induced sleep for a while as the flu has gotten me down

[133MHz]

What is the 'green bit' you are talking about? The entire CPU board?

[kite200]

i think she means teh green cap

[133MHz]

That thing is some sort of multi-turn variable capacitor thingy for the clock circuit, there's no sort of measurable voltage there.

[security16]

  yeah the green cap
seeing as that won't have any voltage going through it i am now at a complete loss as to what the hell is wrong with this thing the grey screen is making me sad

[133MHz]

What kind of electronics tools do you have at hand ? (multimeter, oscilloscope, soldering iron, etc).

I don't know the pinout of the ribbon cable which connects the RF board with the CPU board (I see it has 7 pins, at least four of them should be +5V, a ground, video signal (maybe weak) and a weak audio signal, but what about the other 3?) If somebody knows please tell us.

I suggest testing all 7 ribbon pins for +5V presence. Use a known ground point for the multimeter's negative test lead (such as the 7805's heatsink) and with the positive test each one of the ribbon pins. At least one of them should carry 5V, and then with the Famicom unplugged test for continuity (sometimes called diode test on some multimeters) between the known ground and the ribbon pins. At least one of them should be conducting. That concludes if the CPU board is getting power and helps us narrow down the problem to a specific area.

[Senshi]

Allright, I purchased a Famicom a while back but never got around to hooking it up, in my idiocracy I hadn't realised that an NES RF switch could replace the wierdo JPN one. Anyhow, I also read that for an American television to be able to display the image, the Famicom must be set on "Ch3" and the actual television "Ch95" again, not a problem.

except for this...

http://img253.imageshack.us/img253/7446/famicomswitchprob1gw2.jpg

again...

http://img253.imageshack.us/img253/6167/famicomswitchprob2sk0.jpg

What the heck? There seems to be no , well, "switch" for the chanel selector... no black knobby , if you will. So... I'm stumped.

I haven't been able to hook it up and actually see as I'm in need of a TV that'll go to 95 ( My friends flat screen can, so i imagine that'll work) But, it really concerns me that this could be a major problem.

If anyone may be able to help in any for or fashion, please do.

Also, I'm new here, and I just wanna say it's a wonderful site/forum.

[satoshi_matrix]

I would summeise that the switch either broke off or is stuck. Why not dissasemble your Famicom to see what's going on? The ottom is only kept in place by I think 8 screws and with while you have it apart it also might not be a bad idea to blow some electric, non-static cleaning solution to clear any exterior dirt dust and grime that's been building up for the last twenty years.

[133MHz]

It looks like a recessed switch, the kind you move with a fine pointy object, like a small screwdriver.