Tech Support: "What happens when you turn the computer on?"
Customer: "The screen just stays black."
Tech Support: "Is the computer plugged in?"
Customer: "I took it to a repair shop last week, and they apparently fixed it so it doesn't need a power cord anymore."
Tech Support: "Is the computer a laptop computer?"
Customer: "No, but they never gave me back the power cord so they must have fixed it so it didn't need it."
Tech Support: "Go back to the repair store and get your power cord back. They just forgot to give it to you."