GameGear sprite glitching

[Syntax]

Recently modded a Gamegear that refuses to start on initial power up, but on second try it starts everytime.
I call it Anchorman syndrome..
It was DOA and needed a fair bit of work to get up and going.

Other than that quirk its been fine but Ive noticed when I play some games from master system they have sprite glitches.

Here's a short video, I'm lazy so its sideways sorry

https://www.youtube.com/watch?v=g7qwQ7Haieg

I figured it was a poorly placed pixel clock wire so I replaced it just now with some shielded rca cable and still exactly the same results.

Any ideas??

[GigaBoots]

I'm not entirely sure what I'm supposed to be looking for in the video clip. Can you clarify? Also, it would've been great if you had rotated.

[Syntax]

Sorry, look at the sky centre screen, it shows the score and sometimes half a ring.

[beharius]

Have you tried using a short coax cable with a ground connection? It should be separated from others.

[Syntax]

Umm that's what I said I thought would work and tried.

Shielded rca cables is coax..