AV troubleshooting tips

I work at a college doing AV and 95% of AV problems are solved by simple things.
  1. Is everything turned on?
  2. Is a cable broken or unplugged?
  3. Is it switched to the right input?
  4. Does some setting need to be changed?
    (Resolution, display setting, etc.)
  5. If that didn't work... cycle power.