SNES cartridge problem

[rlaw]

Super Mario World plays fine for parts of each level, but at times there is suddenly a wall of corrupted-looking tiles that Mario can't walk through. Sometimes Mario can jump up and hit the blocks and a whole row of blocks get bumped and all drop out keys. It makes some levels impossible to complete. I've cleaned the contacts with Acetone and taken the cartridge apart. Everything inside looks fine. Could it be a battery problem, a capacitor, or are the chips bad?

[TheDomesticInstitution]

I would assume that you've tried plenty of other games on the SNES, just to make sure it's not a problem with the console. That said... I would suspect the capacitor first. I have several games with dead batteries, and one with no battery (as in it was removed) and they play fine. I don't know if it's cost effective to replace the capacitor, but if you have a spare on hand I'd try it first. I know in other electronic devices that capacitors are often changed when problems arise. Especially in arcade games. The only thing is- I haven't heard that problems with carts that are remedied with new caps. I would assume in the future, caps will have to be replaced in carts to keep them working. Although currently, carts are rarely the culprit. You may examine the cap to see if it's bulging or is leaking. Although some caps can't be deemed faulty by a visual examination alone.

[rlaw]

Other games play fine, even SMW plays fine for the most part. It's just a few locations on each level that have the glitch. There are two electrolytic caps inside. Both are 6.3V 22uF. They both look fine, along with everything else on the board. It would be very surprising to me if a faulty capacitor could result in the issue I'm experiencing. It seems more like a problem in the RAM or ROM because it only occurs at certain points in the game.

[TheDomesticInstitution]

If it's any of the chips then it's a waste. The only way I'd try the caps is if I had a few spare on hand. It doesn't sound like the caps, but it's the easiest thing to try. Maybe check for cold or broken solder joints? If anything looks suspect- reflow it.