Hello apple byte

I'm the owner of Iphone 5S

problem:
- screen have yellow color around the edges (is it normal?)
- iphone restart by itself (no update or anything)


- the vibrate mode keep turning on/off by itself (the switch was untouch most of the time)
i didnt put into vibrate but the phone suddenly "zeet, zeet", check no messages or calls
it keep on "zeet, zet,zet,zet" for no reason
if i put on vibrate n turn it off
the notification vibrate gone, then few hours later, same thing happen again
sometime my notifications didnt sound any incoming message even tho got message coming in

what is the problem actually?
is it hardware or software usually?

IOS 10.3.1, Iphone 5S 32GB.

hard reset didnt work out.

thanks,
usually how much it cost to fix the battery and flex cable in the market?

funny tho
went to Machine centres once i spotted the yellow edges
the worker at customer service said "it's fine, nothing wrong with it"