Genesis 1 video jumping/cutting out

Hey guys,

So a little over a year ago I got a Genesis 1 and started messing with it. Bought it from a lot as-is with no power or AV cords. I ended up grabbing a 3rd party power supply and a RGB cable off eBay.

After cleaning up the system and getting everything setup it works fine with the single exception that the video randomly jumps. Here is a video of the jumping/cutting out
I played through all of the green hills zone with only minimal jumping I did however have the screen completely cutout for about a half second or so at one point but that only happened the one time in the 10 mins I was giving it a try.

I am leaning to think that the cause of the issue is related to the cord rather than the system, all the caps look good. Now when I pulled up SCART schematics it seems that there should be either a 100 or 180 ohm resistor between pins 8 and 16 which my cable doesn't have. Is it safe to assume that this would be something that could cause this issue or am I looking in the wrong direction?



have looked at all the caps and they all look good as I've read that was one of the more common issues with the Genesis, my thought are on the cable.... I've seen a few different diagrams for wiring up the SCART plug and I'm not so sure if my cable is wired correctly.
have looked at all the caps and they all look good as I've read that was one of the more common issues with the Genesis, my thought are on the cable.... I've seen a few different diagrams for wiring up the SCART plug and I'm not so sure if my cable is wired correctly.

 

My first guess would be the TV's scaler chip. It probably has issues with the noisy video signal, trying to correct it with sync reconstruction.
It is not the resistor you mentioned. That one is for the RGB / FBAS selection. If you already get RGB, then this isn't the problem.
You can try a few things now, like adding a resistor in line with the video signal. It forms kind of a low pass filter and on my scaler, it helps reduce some artifacts.

 

maybe the c-sync mod will help : http://www.mmmonkey.co.uk/console/sega/md-sync.htm

 

I have the system running through a sync stripper and a GBS-8220. Now a while back I was able to test a friend's console on my setup using the same cable with his first party power supply, still my TV which is part of the reason I was thinking it was a cable issue.

This looks promising I'll read up a bit more about it later doesn't seem all that difficult to do as well which is a big plus.

 

Oh, if it's the Gonbes, then I'm now sure it is a "coasting" (sync recovery) problem. I've just fixed it on mine
Do you use the original firmware or do you have anything attached to mod it with gbscontrol?

Edit: Yea, using csync should fix it. It comes with its own problems on the Genesis though. You definitely need a ~220uF capacitor in it.

 

I haven't updated any firmware on it and all I have hooked to it is a sync strike which is what I feed SCART feed into splitting audio out to the screen

Edit: Just note that I have SNES, NES and N64 all modded and running through the same setup with SCART RGB and none of them have any issues jumping or otherwise.

 

Let me guess: Your SNES very rarely jumps a bit. Like once in 2 minutes?

 

I honestly do not recall the SNES jumping, I guess that means I need to bust it out and play for a bit

 

Well, it's a 50/50 chance. I just know this scaler well from experimenting with i2c commands.
It can be really nice if all the stars align. 240p support and great colors and all.
But most often the sync control is just too annoying.
If the default firmware gives you these issues, you can always try pushing the "down" button on the scaler.
A brief push should automatically adjust the sync parameters. It sometimes even works

 

I plugged everything up and tried to adjust the sync parameters like you mentioned and it actually appeared to clear everything up. I played the first few zones of sonic 2 last night and didn't notice any skipping