7800 display issues

Dire 51 · May 8, 2017

I was recently given a 7800 by a good friend of mine. It works pretty well, although from time to time games don't fit properly and other times, it takes a while to get a game going. They all eventually work, though, even some of the ones that are known to have problems (Robot Tank, Time Pilot, etc.). Given that, I'd like to keep it around.

However, the more I've used it, the more the picture quality has gone down. The picture is always snowy to some degree, but it's the worst when you first turn it on and the screen's almost white. Jiggling the cable clears it up somewhat, at least until you switch games. I don't know if there's something loose inside the console causing this, or if something's just going bad, or what. I know there are various video mods that can be done - I'm going to be getting an S-Video modded 7800 from a friend at some point, but like I said, I'd like to keep this one around too.

Can anyone recommend someone that can do either an A/V mode, S-Video mod or both? And how much does those kind of mods usually go for?

Edited May 8, 2017 by Dire 51

+-^CrossBow^- · May 8, 2017

For the 7800 there are a number of options. The problem is, at least for me, was that I've tried several different AV modifications and they all exhibit some issue or another. And this seems to be true with all 7800s in that no two of them ever seem to be alike.

But...the AV mod I'm using is s-video only, and so far produces the best overall picture I've managed to get. I do still have my old LHE s-video and comp AV mod that I took out of my 7800 because it was showing odd issues visually. But, it still worked and honestly on a CRT the 7800 with the LHE looked great in both comp and s-video. But since I use a flat panel LED as my primary display, I had issues with color bleeding and other contrast issues.

So.. the two main options I can recommend are:

Ordering the LHE kit for DIY installation from Electronic Sentimentalities here:

http://electronicsentimentalities.com/Assembled%20Mods.html

Or send a PM to the forum member known as Magic Knight and see if he has any of his DIY boards available. However his kit is s-video only and doesn't provide a composite out and requires killing the RF as well to prevent additional noise in the video.

But again these are DIY kits. Not terribly difficult to install with Magic's kit being one of the easiest to install. But again s-video output only. The LHE is a bit more complicated as it requires removing an IC off the board along with a few other components but not too bad. Most difficult part of the 7800 installs is modding the case as the plastic on the 7800 is quite brittle. I use a forstner bits to make the holes on my mods.