Led white circles, spots etc
The white circles are caused by the LEDs not being aligned correctly with the light guide or diffuser.  The backlight of a TV is an array of LEDs that illuminates a diffuser/lightguide that shifts the point source of the LED into a uniform white background.  The spacing between the diffuser and lights is critical for it to function.  If they become misaligned you get the effect you see there.  Usually this can be fixed by removing the casing from the TV and putting the diffuser back into place.

That won't fix the dark voids though where the diodes have failed though, so probably the TV is junk unless you want to go about replacing the diodes.