N64RGB flickering screen on RGB

Hi,

got finaly some RGB cables for my N64RGB mod from etim.
Problem i have is that the screen flicker on RGB output. Sound is normal.
I cut the composite out on my N64 board and use the V point on CS# point on the rgb board from the etim board. http://etim.net.au/n64rgb/
Looks for me as an tribial problem but i dont know what i maybe missed...

Here a screen:



Anyone know what the problem is?

regards
Chris

 

That looks like a sync isse to me. Unfortunately I don't have any experience with those N64RGB boards...

 

Have you tried the CS75 for sync? I thought most devices wanted 75 Ohm sync, not TTL.

 

It could be that the c-sync level is 5V while your TV expects 0.7 Vpp. Just a thought, I have not actually measured it nor do I own a RGB board by Tim.

Old tube tv's usually don't care much and neither does my plasma but Samsung TV's are known to be picky.
Why don't you use C-Video as Sync? Or maybe Luma.

 

Im Sorry i used the CS75.
I cut the composite V Video signal and connect the pin to the CS75 port on the rgb board like this:





Im pretty sure i have no short or something i dobble check anything with my multimeter... Without the CS75 = no picture, with the cs# = no picture

 

That looks horrible...

 

CS# is a LVTTL signal with 330Ohm output impedance. If you connect that to a device with High Z input, the signal stays at Upp=3.3V. If your device has 75Ohm input load (TVs in general) the signal drops to Upp=0.61V.
CS75 has 75ohm output impedance and is designed to have Upp=0.61V if you connect that to a 75ohm load. You should use that (or Luma or C-Video) on TVs for syncing, in general.

I agree that Samsung TVs are a bit picky. I do have one, too

I also think that your issue is a sync issue. Please try to add a 220uF-330uF electrolytic capacitor between the CS75 pad (plus) and the MultiAV (minus). Does that improves your image stability?
If not, could you please share some more detailed pictures of your installation?

 

Thanks guys!

I connect RGB from the RGB Board to the N64 like in the picture above.
Than i cut the csync and solder the CS75 pin to the Video pin.

The installation guide say:

"
The original composite video signal is normally used for sync. Some people claim this causes a small amount of interference to the RGB video (particularly with cheap cables). There are two ways to solve this problem.

• The first is to cut the track to the composite video (V) pin of the A/V output socket and connect a the CS75 signal to this pin. The disadvantage is the console will no longer output compostie video

"
thats what i do.

update:

Here a shot of my N64 socket



I try port 7 and 8 also but no picture..
Next step is the capacitor..

 

Have you confirmed with a meter that trace is cut 100%?

 

I have no more composite out, so i think its cut ^^

Put a 220uF between CS75 (+) and Video pin (-) result = no picture

 

Along borti's train of thought...are there caps in the cable itself? What's the pinout of the cable like?

 

Try with luma (Y) as sync. Make a bridge (Y---V).

 

luma bridge work!
But when i connect the rgb cable to my xrgb3 i switches only between 15/30/45Mhz .