How to buy a used laptop safely

• Check the body for cracks and the hinges for looseness.
• Test every key, the touchpad, the USB ports and the screen for lines and dead pixels.
• Check the battery backup honestly; ask to see the battery health.
• Run it for 15 minutes to see the heat and the fan noise.
• Check the specs in the system information, not only the sticker.
• Get a receipt and a shop warranty.

Avoid sellers who do not let you test the laptop.