(N64) Strange diagonal lines in solid colors

A few months back, I bought myself a secondhand N64 that came with an Expansion Pak and some damaged but otherwise working Composite cables. Not long after then, I started noticing some strange diagonal lines that are very visible in some games, but not others. As an example, they are very present when I start up a track in F-Zero X; specifically in the mostly solid colors that are used on the track textures. The actual lines are static, and really only affect the brightness of the area that they are displayed in.

Since then, I have purchased Official Nintendo composite cables, and in a completely unrelated purchase, upgraded my TV. I also managed to snag myself an Everdrive, which actually prompted me to create this thread. When the Anti-Aliasing patches that this community has created are used, the lines are even more visible, making me think that it could potentially be an issue with the console. I have searched far and wide for a cause for this, and haven't managed to find anything on it. If I am freaking out over nothing, though, I am sorry.

When I get home, I will take and attach pictures to this post. Until then, I hope my description has at least explained the issue well enough.

 

I have the same thing on my N64. I RGB modded it and it made it even more pronounced. If it's the same as mine, then it's called a checkerboard pattern. Apparently it's because of composite sync. I haven't been able to fix mine.

 

There are two things that can make those diagonal lines. Dithering is made by the N64, crosshatch/checkerboard pattern by a bad av cable.

- Dithering: That is just something you have to live with, the N64 was made for tube TVs and modern TVs don't make the dithering look good. F-Zero uses insane amounts of dithering.
Screenshot of Cen64 emulator showing this dithering effect in F-Zero X (using an emulator here to make sure it's not related to a bad video cable).


- Crosshatch pattern: The composite video signal is prone to interference, so you need to buy a high quality S-Video cable. Or if you have an RGB cable make sure it does not use composite video as sync but instead either luma or c-sync.
Image of Super Mario 64 showing the crosshatch pattern.


To differentiate between the two, the dithering effect affects two lines, then you get two clear lines, then again two lines with the dithering while the crosshatch goes through the whole image without interruption.

 

It indeed is the Dithering that is shown in the emulator, and I am once again freaking out over much of nothing.

I'm used to dithering in older games, but the way that F-Zero handles it is quite strange. I will admit that I am amazed at how well just the composite signal shows up on my Display, given that it is an effective 240p image being blown up to 4k without the crosshatching. Thanks for the help, though. I should probably look in to some sort of a Mod to make it look just a little better.

 

What motherboard revision is in your N64?

 

I have no idea, since I am yet to get the screwdrivers needed to actually open my system up.