That's not dead pixels.
I recently bought a Mi box S for my TV to get some features I couldn't get with the built in smart features of my TV. After a week of usage a line (of dead pixel) appeared. Just wanna know if a faulty HDMI can cause it.
There's no problem with the video tho, not sure if the hdmi cable is really faulty.
To my knowledge no box, or HDMI cable,. Can be the "cause" of dead pixels. These are just something that happens as a fault of the lcd panel.
display manufacturers typically have some verbiage in their warranty of what is considered as a problem or acceptable amount of dead pixels .
Almost looks like some slight color banding.
Switch to another HDMI and see if those dead pixels are still there, if yes, it’s your TV otherwise the Mi Box is defective.