One potential such problem is that the TV will seemingly be on, with the power light visible, but there's no picture, just a black screen. Specific to Vizio TVs, this is likely a common concern ...

After unplugging the power cable and then plugging it back in, the TV booted up. This is an isolated issue, but still weird nonetheless. Should you buy it? Vizio's 65-inch 4K OLED TV is so close ...