image flickering and dying out

i have seen people with similar issues E.G. There's some weird situation going on with the video on my old Wii

this is my first ever attempt at repairing old consoles, so any help would be amazing, especially on what tools to buy. I bought a wii as junk and it has a bunch of data from old games, so im assuming problem caused by accident or overtime wear, and what i can analyse so far is that maybe either the AV pins are bent, or GPU fried, what should i look further into or tools to buy for it?