Chosen Solution
always after start,wake up or restart my display flickering and its stops after a few minutes.When is plug to external monitor through HDMI port it works fine.It is video chip bad or display(it has also a few vertical thin green lines,but they don’t anoy me yet :-) )
It sounds like your backlight LED driver is starting to fail. Here is an image of your logic board: Backside of logic board. The chip outlined in Black (Linear Technology LT3957 B29255) is the failing part: Often the solder joints are corroded from a spill getting through the keyboard. I would recommend cleaning the area with isopropyl alcohol (85% or better) to see if that fixes things.
Sounds like a display issue due to the vertical lines. Intermittent flickering can occur on Retina screens when damaged
