Famicom/FDS block artifacts and text issues

[FoxNtd]

I've searched far and wide to find info on this problem, including some digging in the threads on this very forum. As a last resort to find a solution, I'm re-posting my thread from the DP forum here in hopes that someone has a clue what is going on here. I'd like to note that I have another Famicom on the way so I will be able to eliminate some other variables I might have with the tests I've been doing with this console to ensure I can't repro anything on a new console.

Here's an updated copy:

I've been plagued with this problem ever since I got my consoles. Ever since I repaired the FDS by installing a new drive belt, I always thought the issue was the FDS and/or the RAM adapter. I even cleaned the RAM adapter contacts and got no change. There is an unpredictable but reproducible video/visual artifact problem.

Everything is entirely playable and the artifacts that appear on screen have no affect on gameplay in any way. The variety of instances of the problem and the frequency in which they occur are all unpredictable with no apparent pattern. The most I could establish from playing is that certain instances are likely and some appear to be entirely consistent (such as the Mario 2 title screen whose example is below.) The following are a bunch of snapshots for both FDS games and FC games showing the problem; I now suspect the issue has to do with the Famicom itself because if the FDS was solely responsible for causing this, then I should not be seeing it occur with FC cassettes, but I do.

Screenshots taken down

The quantity of examples is to eliminate the theory that "oh, it's just a fluke." This is definitely an issue and it's reproducible 100% of the time, even if any one of these example screen shots take a few tries to manifest. Sometimes the "Four Blocks" will appear every single time but other times it might take a few redraws of the screen for it to happen. That's what I meant by unpredictability earlier.

As for the far-fetched idea that I have a ton of damaged games, I bought Legend of Zelda factory sealed in brand new pristine condition, so I'm rather confident there is absolutely NOTHING wrong with that game. The only game I suspect of having some kind of defect or damage is Guardic Gaiden as no other game causes pixel displacement like that game shows.

The Famicom is visually in great condition. Slightly yellowed but otherwise clean and the controllers' buttons feel like they're new, actually. I wonder if a safe cleaning technique should be used for the cartridge slot but I'm not sure. I know there is no association between hardware functionality and condition of the casing but it's a little unusual.

Other games indicate no problems at all. For example, Green Beret for FDS played start to finish without any artifacts on the screen.

I've tried hard, multiple times, to find anything at all online that presents or discusses this problem but I feel like the only Famicom owner to document this issue.

I'm skeptical about opening the Famicom to inspect the internal hardware unless someone has a legitimate suspicion about a particular component that is responsible for this issue... I'm open to ideas I guess.

As already mentioned, everything is fully playable. I don't have trouble booting games. Games don't freeze or crash. Nothing else irregular occurs. Just the artifacts shown above, nothing more.

(End updated copy.)

Last note to make: given the next Famicom I obtain is fully operational, I have no problem selling the current console that I am demonstrating here. If anyone here would like to get their hands on this console to try to investigate and repair the issue, I'm all for it.

[ericj]

Could be a bad/loose chip, cold solder joint, damaged PCB trace, bad RF adapter (I assume this isn't AV modded, right?), or could be something entirely different. It's definitely the FC itself. The only way to figure it out it to open it up.

[ericj]

I'm almost certain that it's not the RAM Adapter since he's seeing the same artifact problem with game cartridges.

[jpx72]

It looks more like the Famicom's PPU or CPU or RAM problem. Maybe partialy burned chip. Could happen by a voltage peak of some sort. Really hard to pinpoint the problem. Buy a new famicom, that's my suggestion. OR open it and re-heat all solder points :/
I had a simillar problem when I socketed the RAM chips inside the famicom (pulled out, inserted a socket and then the RAM chip into it). A bad connection was creating graphical glitches.

[FoxNtd]

The Famicom is not AV modded. The problem cannot be due to the RAM Adapter from the FDS because, as already stated, regular cassettes also reproduce the issue. Lastly, the RF box is not the problem. Already tested the console on a different TV with a different RF box and there was no difference in behavior.

Thanks for the responses guys. All of these seem like plausible explanations and leads as to what is the source of this. I don't have the proficiency to take this investigation further and attempt a repair; hell, I don't even have the equipment anyway. Since I have a replacement coming very soon, I'm gonna give this console up since I don't need to have an extra Famicom. If anyone would like to pick it up, I can send a PM and notify when I make it available to buy.

Any thoughts for Guardic Gaiden, though? That game seems to have a problem of its own. I will definitely re-test Guardic Gaiden once the new Famicom gets here.

[Xious]

This is most likely due to either:

1: Corrosion or filthy conacts on he artridge slot. They need o be cleaned carefully, but forcefully and I suggest locating a SFC/SNES or MegaDrive cleaning kit. A piece of lint on the pins can also do this.

It's a problem on one of the address paths, so you can narrow it down.

2- Otherwise, it's likely a faulty connecion between the PPU and the cart or cart connector: possibly a bent pin in the slot or a cold solder joint.

I wouldn't suspect anything else due to the predictability and precise nature of the artefacting.

Your second unit, if kept clean, will likely be sufficient to solve your reqirements, bu you can always attempt to rectify the issue on your first unit at some future time.