Today, I checked up on some 4-year-old Ledger Nano's, and they all have display issues: the screens are so dim that they are only readable in complete darkness, and a few also had lines running through the letters, making it impossible to enter the correct pin. Luckily I didn't have any funds on them, but a cold storage device on which the display doesn't even last for four years is pretty shitty—just one more reason to avoid Ledger.