Video Problem

[Cojiro]

When I hook up my n64 to the screen that I am using, sound comes out, and the screen lights up, but the video is barely visible.
-I am using the same voltage regulator (TI chip/capacitor/resistor)
-I am using a 9 volt battery. The screen I am using is designed for 12 volts.
-I have tested the screen with other game systems and it worked perfectly fine running off this battery
-I tested the screen with another game system while the battery was powering both the screen and the n64 (not hooked up), and the screen worked perfectly fine
-I hooked up my n64 to another screen, and the video played fine.

What should I do?

[zefeldo2]

I don't know if this sounds retarded but why don't you take apart the video connector and connect the parts needed to hook up to the screen. if you know what i mean

The actual n64 to tv cable

and you take it apart, trace the cable to red,yellow,white

solder the parts that connect to the n64 to the motherboard peice

and try hooking it up to the screen.

probobually the most stupidest things that you will ever hear on this forum but i thought it might (1 in a million) be useful to somebody.

because when I tried hooking it up to a screen it was all messed up and stuff but the regular video connector shows it better.

please don't think im stupid I was just trying to help

[Cojiro]

Are you meaning solder the wires directly to the mother board instead of plugging it into the a/v slot?
I have already soldered the wires on to the pins. I have done all the wiring for my portable; everything is pretty much done. I had this working to the point of being ready to put it all into a case, I was just trying to switch screens at the very end, and I don't know why this is happening.

The screen runs fine with other systems, and the n64 runs fine with other screens, but for some reason when I put the two together the sound is fine but the video is so dim that you have to squint to see just the shapes.

Thank you for the advice, anyone else have any ideas?

[Axaj]

Do you have power hooked up to the backlight?

[timmeh87]

Connect a separate ground wire along with the video signal. How is everything grounded in your circuit?

Are you sure you are using composite video and not half of an s-video signal?

[Cojiro]

The backlight is coming on fine, and the screen itself worked fine when I plugged my wii into it.
I soldered regular RCA cables directly to the n64 motherboard, and when I plugged them into my regular TV it worked fine. Should I still wire a seperate video ground even though the n64 works fine with other screens?
-thanks

[timmeh87]

Well regular RCA cables include a separate ground wire for each signal, so thats kind of where I was going with that.

If perhaps you used really thin wires for the power, and there is no other ground connection than the one for power, then the current flowing across the resistance of the wire can create a difference in potential between the ground planes of the two systems.

Also, you are positive you are feeding a composite signal into a composite-hole (lol) right? And not like S-video chroma signal instead?

[Mario]

You're powering this from a 9v battery? Chances are it's not getting enough amps.

[Cojiro]

Sorry, I didn't mean that it was a tiny little 9V, it is a 5400mAh battery, the same one ben used in his PS2P. It is impossible that flow resistance/power could be the problem because the N64 runs perfectly fine off of the battery I am using: I have plugged it into a TV while it was being powered by this battery connected with the wires I am using, and it worked fine.

I am almost positive that the video out is wired correctly. If it was incorrect it wouldn't work perfectly on the other screens that I have tried. I plugged it in to a regular TV and it worked fine. I plugged it into a 4in psone screen and it worked fine. I can't figure out why it won't work on this one, when practicality dictates that it should.
I do not understand how it could be an a/v out problem when I have plugged the RCA cables into other screens and they have worked fine.

Anyone else's input?
-Thanks

[Mario]

Well, you said it was designed for 12v? If you're only giving it 9v, that can really screw things up.

[Cojiro]

Would it screw things up, even though when you hook up a wii that's wall powered to the a/v input of the screen it plays fine when the screen is being powered by just the battery?

[Mario]

Now that's strange. But it won't work with any other combination?

Maybe it's how Ben's original Atari AV mod didn't work with the PSone screen.

[Cojiro]

I can just use another screen, I thought I'd just come here to see if there was a possible fix to my problem.
Thanks for all your help.

[Cojiro]

Would the battery that I've been talking about using (9v 5400mAh) be too hard on a psone/zenith screen?