1. Don't touch PFC directly by your hands without gloves! Otherwise your fingerprint, sweat etc would leave at the PFC and make the screen work improperly.
2. Make sure you have firmly connected all the interface settings of the PFC. If the screen works improperly, please check those connections again.
3. If you find colored lines on the screen or the screen is not working properly, please clean the screen cable with cloth and reinstall it.
4. To avoid damage during the shipment, I paste a screen protector on the screen hence if you find it "looks like a used one or has some cracks or scratches", just take off the protector.