Red line around screen perimeter
My ipad has started showing red lines around the perimeter of the screen. Does anyone know what has caused this?
iPad Air (5th generation)
The phenomenon that you describe is known as “backlight bleed” - and is often attributable to a defective screen.
The LCD screen has a backlight that illuminates the screen from behind. The screen construction is such that the screen is edge-lit by Light Emitting Diodes (LEDs) distributed around the periphery of the screen; a screen diffuser layer distributes this light across the rear surface of the screen to provide even illumination across its full surface.
The diffuser is a laminated component of the LCD screen. In some circumstances, this layer can de-laminate from the LCD - allowing light from edge backlights to leak (or “bleed”) into the visible edge of the screen - this effect being most noticeable in dark environments with a bright screen.
The only remedy for this fault is screen replacement - which may be expensive. If within warranty, this should be fixed by Apple for free.