There are no problems with the phone; you can check it as much as you like.
It fell from my hand one day, and a dot appeared on the display, which later spread to the full display. I have since changed the display; I did not install an AMOLED one, I installed an in-cell display. I am selling it because I bought a new phone. Please do not offer unreasonable prices; if you want to buy it, offer a fair price and I will understand.