display/power on problems

[huscky347]

Hello all. i bought this phone 4 months ago and 1 week ago i started to have some problems. at a moment phone started to show colour stripes on display and turn off and since then it doesn't start from first time. i try several time and it stay on a while then it turns off by itself, or show colour stripes.sometimes if i run camera display block and turn off.this happend as a coincidence,immediatly after some updates of some apps(and about few days before i drop it on floor but it worked fine almost a week). i did a factory reset,erase cache but no change.phone still doesn't turn on from first start up or it show colour stripes (blinks) then it turns off. do you have any suggestion? i dissmount backcover and check plugs.everything seems ok. what shoul i try?
i will attach a picture with problem of display(how it looks at startup). thank you