Weird SNES problem involving sprites (hard to explain)

[SkiDragon]

I got an SNES with some other stuff at a garage sale for I think $5.

Everything works fine except for the SNES. The system looks in really good shape (no yellowing, no dust even on the inside.). It turns on and the games play. The problem is that when it plays the games, there is a vertical column where no sprites appear. They just jump across the gap, which is rather wide. They are never hidden "behind" it. It is so crazy that I cant even survive a minute in a game I am really good at.

Any idea what could be causing this weird problem? I am sure its not the games, as I tried two that I am sure work fine otherwise. I also cleaned the system and the connector.

I am guessing I wont be able to fix it, but its worth a try.

Thank you.

[The_EniGma]

maybe the cart? try some diiferent carts

[dreamcaster]

Possibly the cartridge port is stuffed? Or maybe just some dirt? Weirdest thing I've heard a SNES doing (considering how un-problematic they are.) :o

[rbudrick]

Hmmm, time to find one of those rare diagnostic carts, hehheh.

Man, I've really never heard of that problem though...can't imagine what it would be. Just for shit n giggles, clean the cartridge contacts. Does it do the same thing whether you use AV cables or a RF switch?

-Rob

[SkiDragon]

I have a feeling its a screwed up video processor or something. I cleaned the carts (I always do) and cleaned the connector in the system right before I tried this. Like I said, the system appears to be in really good condition, with no yellowing or dust. I suppose I could try an RF switch, but I would have to dig one up somewhere, and I doubt thats the problem.

An example of what is does is, in Darius twin, the words "game" and "over" are separated by a really large gap. As are some of the menus. Its really screwy.

[FABombjoy]

Sounds like a RAM issue in some kind of video frame buffer. Since that type of memory is written to but never read back from, the game keeps truckin along without crashing but parts of the screen are missing.

[SkiDragon]

I should point out that the background is usually, or perhaps always, normal. No gaps there. Im guessing this problem is virtually unfixable, but I could be wrong...

[davidleeroth]

I'm going for the RAM too.
I've had one of those as well plus sometimes the sprite edges were missing. I went through the board with a multimeter but saw nothing wrong.

[The_EniGma]

can u take a pic of ure tv screen when playing maybe we can help u more...

[SkiDragon]

Next time I get a chance, I will.

[SkiDragon]

Double post. Will put pictures here ASAP.

[The_EniGma]

hM..... i think it was ethier the NES or SNES which had some faulty chipsets which nintendo recalled and changed for free......


Maybe just Mayeb you have a faulty chipset model and didn't return it?

hope that helps

[Predatorxs]

It sounds like the snes pin set, make sure there is nothing in there.. even abit of lint, or thick dust?? hell get a hoover and give it a quick run over the top of the cart insert, so you can see the pin set!

:vamp:..XS

[SkiDragon]

Here are the pics, taken with my poor quality camera.

http://img.photobucket.com/albums/v282/SkiDragon/snes1.jpg
See mario in a weird spot, then look at the level name. He is supposed to be on the water level I think.
http://img.photobucket.com/albums/v282/SkiDragon/snes2.jpg
The flower is messed up.
http://img.photobucket.com/albums/v282/SkiDragon/snes3.jpg
The beginning of Super Mario World, "Nintendo Presents"
http://img.photobucket.com/albums/v282/SkiDragon/snes4.jpg
The main menu of Darius Twin.
http://img.photobucket.com/albums/v282/SkiDragon/snes5.jpg
A messed up fish.
http://img.photobucket.com/albums/v282/SkiDragon/snes6.jpg
Title screen of Darius Twin. "Darius" spins into the screen, and is not affected.
http://img.photobucket.com/albums/v282/SkiDragon/snes7.jpg
The option menu. The picture in the top has rotating ships which are broken apart, but the camera distorted the image.
http://img.photobucket.com/albums/v282/SkiDragon/snes8.jpg
A solid line of koopas, but the SNES distorts it.
http://img.photobucket.com/albums/v282/SkiDragon/snes9.jpg
Mario appears to be in the ground, but of course this is just another graphical error.


I doubt its the pin connector. I already cleaned that, and I would expect the SNES to simply not work at all if the connector was too dirty.

[Predatorxs]

I think someone already mentioned this but, try a snes cleaning kit... there should be sum on ebay, but go for the genuine Nintendo snes cleaners and not the other 3rd part cleaners!!

:vamp:..XS ;)

[omnedon]

I think it's broken. LOL

If it was harder to find, one of our more knowledgeable members would possibly be keen on taking on an IC level failure like that likely is. However, since this is a reasonably common SNES, you may be out of like, for a reasonably doable fix.

If it's shell is not yellowed, and in nice condition, keep it, and when you get a fugly yellowed one that is beat to crap and works, do a swippity swap.

That's what I'd do.

[MrKitt]

due to the strange behavior of the error i would guess its a PPU problem but trying to change the video ram chips first would be a good bet (easier to replace and easy to find replacements chips)

[Predatorxs]

due to the strange behavior of the error i would guess its a PPU problem but trying to change the video ram chips first would be a good bet (easier to replace and easy to find replacements chips)

I'd go with the Brain Surgery first, alot easier :P

:vamp:..XS

[Jehuty]

Just get another SNES no sense in wasting your time with something clearly faulty.

[The_EniGma]

try that one on liksang its like 6 bucks or something


also ive seen MVS cabs make the sprites fucked up sometimes or something

[d4s]

Sounds like a RAM issue in some kind of video frame buffer. Since that type of memory is written to but never read back from, the game keeps truckin along without crashing but parts of the screen are missing.


just FYI: the snes doesnt have something like a framebuffer.
it renders the images per scanline.

your video ram guess was a good shot, though.
i'd say the oam ram is faulty.

i had a similar error, but with cgram(thats where the colours are stored)

i fixed it by replacing both video ram chips.
you can find them in different carts, such as vortex, yoshis island and such.
however, id say a barebone snes system costs less than two of these carts and is guaranteed to work.
i had some of these carts lying about, replacing the vram was cheaper for me.
besides, it was fun. ;)

[omnedon]

Thanks for the info d4s! Practicality aside, by posting it, you've etched it onto the accumualted data that is this forum.

Great stuff!

[Duncan]

More reasons why I love this forum. Awesome investigation, everyone. :hail: