Getting signal but black screen about arduino-tvout HOT 5 OPEN

WB7ODYFred here, This TVOutBeta1 code worked great on my OSEPP Arduino UNO 
board a year ago.  Even the Audio output fed into the TV audio input ( RED RCA 
jack, or White RCA Jack). 

Visit this instructable and re-check your wiring setup to the atmega 2560.  
Maybe different pin numbers are used for the atmega 2560 board than the UNO 
Board.   Realize the difference between Arduino PCB Board PIN numbering and the 
actual microcontroller pin numbering.

from http://code.google.com/p/arduino-tvout  Arduino PCB Board Pin Numbers
                Sync    Video   Audio
m1280,m2560 B 5 A 7 B 4
UNO             7       9       11

http://www.instructables.com/id/TV-Out-with-Arduino/?ALLSTEPS
I give the source code for my test pattern that you can test for yourself on 
your atmega 2560.  You might have to change the SYNC, VIDEO, AUDIO Port Output 
pin numbers in the TVOut code section to match your atmega controller pin 
numbers.

Wish you well on finishing this project.  Comment back here, both with 
questions and what you did to make it work.   Best wishes,   Fred

These resistors Sync 470 ohms &  Video 1000 ohms worked with 5V power supplied 
to the Arduino UNO Rev. 3.   Is the clock frequency 16 Mhz on your board?

If you are running the Arduino with 3.3V power, then change the resistors to a 
different value Sync 270 ohms and Video 680 ohms.
See this web page of information that was also given above in Issue 66.
http://www.incrediblediy.com/2013/03/connecting-arduino-pro-33v8mhz-to-tv.html

I do know the pin differences and I know that both operate at 5v and I'm using 
the correct resistor values.  I will check on the clock frequency.  That may be 
my problem.

So the arduinos are all 5v at 16mhz and everything seems correct but still no 
video.

Im having a similar problem with my arduino. For some reason on the RCA hookup 
it wont work with the resistors although if i just hook it directly into the 
board without resistors it works any idea why the resistors wont work with the 
RCA setup.