I am using a radioshack 9V power supply that is like 15-20 years old, probably. I am going to switch it with a working power supply and see if that helps. Thanks for the help guys..
Yeah, that probably wasn't the greatest idea ever. The NES adapter used AC (for some goddamn reason) and wouldn't cooperate with DC that great. Before I got an original NES power adapter, I used a 9v power supply from a Genesis, which was reccomended by many, many other websites. It made the system heat up quickly, sometimes not read games, and it always made an annoying hum through the TV.
So yeah, switch it as fast as possible. If there's still any problems, then, well, I'd suggest sending it to someone who can fix it.