: Use the command prompt ( powercfg /batteryreport ) to check the "Full Charge Capacity" against the "Design Capacity". Aim for 80-85% health or higher.
: Plug a device into every USB, HDMI, and charging port to confirm they aren't loose or broken from frequent use.
: Fans in display units can become choked with dust.
: This is the most critical check, as demo units are often left plugged in 24/7, which can degrade battery capacity.
: Check for "burn-in" (ghostly images stuck on the screen) or dead pixels, especially on OLED models.
: Open a solid white or black image in full screen to spot any discoloration or stuck pixels.
Before you buy, perform these physical and technical checks in-store to ensure the "deal" isn't a dud: