SNES Mario Kart bad graphics... other games fine?

[Mr Bond]

Ok, weird one here. I’ve got a SNES, quite a few games with it. Killer instinct. Mortal Kombat, mario word, Jurassic Park and a few others. They all work fine.... apart from Mario Kart. It runs and menu screen is fine but when on the playing screen the graphics are messed up, as in there’s horizontal lines accross the screen.

Bought another mario kart cartridge off eBay... same thing! All the other games work fine.

Anyone any idea? I know some SNES carts had a special graphics chip or something in them... or is it a problem with the SNES? Even though I’ve tried two mario kart cartridges.

 

[big10p]

I would guess your SNES has a fault with it's graphics mode 7 operation. The other games you list that work don't use this mode (I don't think), but pretty sure Mario Kart does. Most racers on the SNES use it. Try another mode 7 game if can, and see if you get the same fault.

 

[Flinnster]

Yeah get pilotwings and see if the same things happen.
If it is mode 7 the lines should be just through the background, and not through the character / player sprites at all.
The SuperFX 'Mario' chip is not in early games like MK, so it won't be that at fault.

 

[Mr Bond]

Thanks guys

 

[Rich]

Yes, had the exact same problem, weirdly it seemed to fix itself after a while but it's a mode 7 thing, there are forum threads out there describing what the technical poblem is but essentially something is faulty in your SNES and you may need a new motherboard as I think it is pretty tricky repair otherwise (replacing a chip)

 

[Steveylou]

I had the exact same problem with my Super Famicom at one stage. As others have said it's an issue with one of the PPU chips on the motherboard that deals with Mode 7. From the games you have it won't just be Mario Kart. There are some Mode 7 effects in Mario World (some of the boss stages are set on rotating platforms) and you'll likely find those will mess up too.

I ended up just buying a cheap, tatty, unboxed Super Famicom from eBay and swapping the mother boards over. It was surprisingly easy to do. You will need a special Nintendo screwdriver but they're only a couple of quid from eBay.