Loosing Antenna , flashing screen and restarting

Hi there

I've faced a problem since. I lose my antenna signal (on both 3g & 2g or auto connect) frequently, then when antenna signal bars return, suddenly screen flashes to black and back then I lose antenna bars again. and this happens for a while till it gets restart almost every time this happens.

I see multiple wired things also; while screen flashes,
sometimes some apps would stop working like instagram, battery docter, goole & google gesture and ...
sometimes i see a notification stating my sd card is damaged and needs format! (some times sd card is empty!)
and like that...

while restarting when samsung logo or even note 8 logo comes up, I see these flashing screen continus

I guess these happens while I am at areas with not very satisfying signals, although I had this problem while I had no sim card in it too!
what is wrong guys?

Note 8 5100
android 4.4.2 official ROM
(I thought of it as a software problem and upgraded to kit kat but no chance!)

[help] Loosing desktop shortcuts on reboot

Hello,
I have a problem with latest fw that was supposed to fix stagefright...

I loose some of my desktop shortcuts on reboot. The apps are in the sd card, but before the update they were replaced temporarily, while sdcard gets ready...

Now they are just gone and I have to search the app drawer again and again...

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