Nintendo 64 hardware

Recalibrate controller:
Make sure the Analog-stick is centered. Then, hold L + R and press Start.

Control Pak manager:
Hold Start while powering on the Nintendo 64 with a game that recognizes the Control Pak memory card. Most games will display a file management system that allows file deletion and other features. Some games will also allow the internal cartridge saved game files to be mangaged.

Rumble Pak glitch:
Some older games will not start if a Rumble Pak is plugged into any controller on the system.

Use your own music in games:
Buy an AV plug with a speaker link at the end. Take out one of the audio cords on your console that connects to the VCR or monitor. Plug in one of the AV cords into your VCR. Connect the end of the AV link to a portable CD player into the headphone jack with your music of choice, while making sure that the console still connects to the VCR in the same place. Turn on the Portable CD player. Turn on the video game console. Start a game, and turn the sound effects volume up while turning the music volume all the way down. Note: Some games do not have this sound option. Pick a track and play it on your portable CD player. In the game, you should hear the sound effects perfectly while the CD player's music is being played. Note: You can use tape players and radios in place of the CD player if they have headphone jacks.
Information in this section was contributed by Logan Peter McDonnell.

Trouble-Shooting -- if this does not work:

Check if the CD player and console are both plugged in.
Check if the CD player or console is on.
Check if you can turn down the in-game music volume.
Check the reasons in your console's manual why it is not working.
Check the reasons in your CD player pamphlet why the CD is not working.
Check to see if either of the CD's are scratched.