SNES black screen issues with only certain games

[KuiperBelt]

I recently picked up a SNES from a friend who wasn't using it anymore, and I've had issues when trying to play just two games: A Link to the Past and Donkey Kong Country 2. The other games I've tried, Super Mario World and Star Fox, have worked fine.

When loading LttP, I get through the opening triforce to the file selection without a hitch. I can create a file no problem, but when I attempt to open the file I am greeted with only a black screen and the noise of the rain from the opening scene (I'm starting a new file)

With DKC2, I can select a file and get to the world map and select a level, but the screen also goes black without loading the level. It keeps playing menu music. Once it popped up an error and told me to restart the console, but only once.

I've opened both the console and games and cleaned contacts and connectors thoroughly with alcohol. Mostly I just want to see if anyone knows the console or the cartridge is the cause of failure. Thanks in advance!