Question Questions involving grounds

[aMammoth]

Alright so working on a n64 portable. I just finished relocating the cartridge slot. I have removed the plug for video out from the console board, And soldered yellow,white,red cables to the correct spots. I am still using the original power supply at this point.
My question is ... what do I need to do for grounding the video?
Do I just run a wire from the spot for the ground over to a ground where the power supply connects?
Or do I connect the bare copper stranded wire that was wrapped around the video and audio cables together and then connect it to one of the two video out grounds?

I am pretty sure that if I was powering the console by battery I would just run a wire from the negative to the video out ground. I'm just thrown off due to the original power supply still being in the mix.

 

[Shank]

Ground is ground is ground. Connect to any of them and it'll work, they are all the same.

 

[aMammoth]

Alrighty, cool deal. Many thank you's.
Is there any alternative contacts for left and right audio and video? I may have lifted one of the contacts

 

[GC64]

I know this is accurate for revs 1-4, not sure about the rest