ntsc

I have a 5231 turret cam, and I see that it is set to PAL and I want to change it to NTSC. Can you help me change this? Thanks, R

I changed the video setting from NTSC to PAL and now the screen is blank. I removed the battery turned it on and off then replaced the battery. I hit the reset button on the board. I held the stop button and a combination of the above. How do i reset back to factory?