Weird scrolling issue ? NESRGB

[perceusedewalt]

Well, I've been playing with my RGB modded NES on a crt for a pretty long time and I noticed that in some games with vertical scrolling there is a weird distortion on the top of the screen. I really don't know how to call it. I always thought my crt was the culprit, since it's old and worn, until I tested it with my new OSSC. Unfortunately the issue is still there, and it's a lot more noticeable on an HD TV.

Do you know what could be the cause ? I'm still very new to all of this so I'm a bit lost. I just hope my NES is not broken and that it's fixable because I spent a lot of money on it...

I'm using Scart cables with csync and sync on luma, and my NES is RGB modded with the Nintendo type connector and the end from a Gamecube.

Here's a video of the issue, it's very noticeable in games like Paperboy, Mega Man 2 and EarthBound.

https://1drv.ms/v/s!AkT9-ql0U4p7i2joA97ZZIR5-b5s

[Hoagtech]

It’s the OSSC.

Your problem looks better than mine actually. I have a weird “S” shape that shakes towards the top of the screen. I think it has to do with the near 60 hz refresh rate of the NES.

A lot of NES games draw too much on the top and bottom of the screen throwing off the screen ratio if you display the entire image so I just stretch it past my bezel.

I believe the de jitter mod by marqs solves this but my interests are towards other consoles for the time being so I can’t say for sure

[perceusedewalt]

Well the problem is also very noticeable when I use it on my CRT (the video is actually showing my NESRGB on my Trinitron with the SB-2840)

[shiftednes]

I am wondering if the reason you see it on your CRT is because the sync signal is being processed through the SB-2840 and it isn't liking the non-standard sync the same way modern TVs and the OSSC has issues with it which is then showing up on your CRT. Is your NES still capable of displaying regular old ass composite or perhaps S-Video if that was installed alongside the NESRGB? Can you hook it up like that to your CRT and see if you see the issue when you remove the SB-2840 and any modern processing from the equation? Like Hoagtech mentioned, the dejitter board might be what you need installed if you want to continue to use your NES through the SB-2840 or to your particular LCD (or an OSSC). https://www.videogameperfection.com/pro ... itter-kit/

[thebigcheese]

It's the jittery sync. Dejitter mod eliminates it.

[nmalinoski]

I am wondering if the reason you see it on your CRT is because the sync signal is being processed through the SB-2840 and it isn't liking the non-standard sync the same way modern TVs and the OSSC has issues with it which is then showing up on your CRT.

I don't believe the OSSC has any problem with unmodified NES or SNES consoles; it's usually the connected display that has a problem with janky syncs over HDMI.