I had a galaxy note 4 for 3 years and then it started to freeze with potential cpu problems. According to the internet there is a class action lawsuit due to this specific issue. I had to get a new phone. Money is tight so I took a chance and purchased a used note 8 off Kijiji. I met with the seller and they ensured me everything was fine. I checked the imei online and did sensor and screen tests and s pen tests. So far the phone is great. Very fast. The only thing that is bothering me that even the seller could not tell me is there are a series of markings under the screen, clearly not damage, along the top and bottom. There is also a code at the top left most corner of the screen, D8AD9. I have attached photographs of these weird markings. I luckily have my own microscope and when I looked at the markings and code they were all deposited under the screen in the same silver material. I went back and forth through email with the seller through Kijiji, they eventually gave me their email address so I could send them photos. As far as I can tell the seller seems to be genuine in their explanation. He got it 2 years ago from a friend who worked at samsung. He said the phone is flawless and those markings have been there since day one. I took it to a few different cell phone places and one said it was screen deterioration but clearly it is not as I looked under the microscope. The other had never seem this before and said could be a really good fake or replacement screen or a samsung intro or demo model. I looked at videos on YouTube to figure out if it is a fake and so far the phone seems genuine. Please look at the photos and give me your honest opinion. The seller said they never replaced the screen. I hope I did not get scammed. Thank you.