Sync on N64 Rev-04

Yes, plug the cable in with the console taken apart. Follow this pinout if needed: http://www.gamesx.com/wiki/doku.php?id=av:nintendomultiav

They all work fine, it's just a quality difference. You will get the best quality with C-Sync and the worst quality with sync on composite video.

C-Sync is what you are tapping into on the U4 chip.

Do not send 5V to pin 16. Instead, send it to pin 8 then jump pin 8 and 16 with either a 75 ohm resistor, a 100 ohm resistor, or a 180 ohm resistor. Either of those resistors should bring the 5V down to somewhere between 1-3V, which is needed for RGB mode.

This diagram is for a properly wired NTSC SNES RGB SCART cable. Ignore the composite video line to pin 20. That was just how cheap cables were wired up and the official SFC RGB JP-21 (Japanese version of SCART) Cable.

 

so if I understand this correctly, when I plug the SCART cable in and turn the console on I should see +5v on pin 8, if so there should be a resistor between pin 8 and pin 16 if not i should install one?

once I have +5v on pin 16 i should have a picture on the screen, but it will be fuzzy. then I jump pin 14 from U4 to pin 3 of multi-out with 680ohm resistor?

 

Yes and yes. To test SCART pin 8, touch the black lead on pin 14 then put the red lead on pin 8. Also, check to see if the N64 is outputting +5V on the Multi-Out. It should still be there but it may be possible that the signal was removed since S-Video and Composite Video cables do not use it. To do this, just connect the black lead to a ground point on the N64 then put the red lead on Multi-Out pin 10. You don't need the cable plugged in for that. Make sure the system in on while doing this.

Try to keep the legs of the resistor short as possible and use a wire to extend it to avoid hitting any nearby component legs. Make sure you have the Luma to pin 3 resistor mod you did removed before doing this.

 

So I am completely stumped! The SCART cable turned out to be sync on comp. when I plug it into the the console and turn it on, pin 8 is +5v and there is a 75ohm resistor already installed to pin 16 but when I test I get +5v!?!? The pin out matches the Snes one you posted. I installed the 680ohm for sync as well. But guess what still no picture!

 

Not sure if i'd rely on a resistor to lower voltage to go to a SCART, if the resistor fails it could feed the connector 5v from the 7805, I don't know if that would cause any damage to your television. Another option is to get a step-down regulator, they only cost a pound on ebay.

I haved used these and can confirm they work well.

http://www.ebay.co.uk/itm/DC-DC-3A-...lace-LM2596-/271969895315?hash=item3f52ab4393

 

I said a 680K resistor not a 680 ohm resistor. 680K resistors are 680,000 ohms. Sorry for any confusion. Try upgrading the resistor in the SCART cable to 100 ohms or 180 ohms.

 

No problem I will try the 680K resistor. and upgrade the resistor in the SCART cable.

Am I not getting any picture due to:

SCART Cable not having 1-3v?

C-Sync not enabled?

Amp wired wrong/not working?

 

No picture could be either of those. What amp are you using?

If the SCART cable has less then 1V on pin 16, the TV/upscaler will default to Composite Video mode. A C-Sync wired cable will give sound but no picture.

 

Here is the AMP I made. I used MMMonkey Guide.


I tested with the unit on and I am getting +5v on the white lead.

 

Ok. Are you getting +5V on the +5V pin of the multi-out?

 

Yes

 

So then we can rule out that as the issue. All I can say now is wire up the 680K resistor and see if it gives you a picture. Since you were able to get a picture before with sync on luma, we can also rule out the cable.

 

That is the problem from the beginning, I was never able to get picture!

 

Oh, I misread. Sorry. If you weren't able to get a picture before, then maybe the amp isn't working right? Usually when you have a working RGB signal but no sync, you will get color but the picture will be unstable. I'm sorry if I'm sounding like a broken record or not understanding, I'm just confused about this as you are. I've never done the N64 RGB mod before.

 

here is one question does it matter what order I wire input (RGB) looking at the schematic of the chip I cant tell.



looking at MMMonkey guide he wired it both ways:




any way to test the amp?

 

Not sure, the schematic seems a little confusing. I know Tim Worthington's N64RGB board has C-Sync and RGB on it so maybe that board will give you better results?

 

Does the voltage on SCART pin 16 have to be between 1-3v?

If it's more will it activate RGB?

I replaced resistor on in SCART with 180ohm but it only dropped voltage to 4.7v. I also removed amp and c-sync resistor and ran wires directly from U4 to multi-out to rule out amp,wiring, console and I still dont get and image on the TV.

 

Yes, it has to be 1-3V. Anything more could potentially damage your TV/upscaler's SCART socket. Anything less will give you composite video mode.

That's odd that you get 4.7V after that. You should be getting voltage close to 1.5V with an 180 ohm resistor. The mod requires the amp, it's a weak signal without it. C-Sync requires the 680K resistor to bring it down to TV sync levels.

 

So I got my hands on another console (NUS-CPU-03) but I am getting +1.2v on the +5v pin of the multi-out!? I know this rev has sync components installed so I'm hoping I get better results.

 

That's really odd. Nintendo is a strange console maker... Hopefully this one works better.

Yep, N64's before the NUS-CPU-04 have C-Sync already wired so just do the RGB lines and you should be good to go. If it still doesn't work, try Tim's N64RGB board.

If it isn't enough to drive SCART pins 8 and 16, use an external +12V DC power supply. Simply send the 12V to pin 8 then jump pin 8 to pin 16 with a 560 ohm resistor. This should enable RGBS mode and switch the converter to a 4:3 aspect ratio (set your TV to 4:3 or it will be stretched).

If the console can drive both pins, then simply wire +5V to pin 8 then jump it to pin 16 with a resistor with a value somewhere between 75 ohms and 180 ohms.