S5 reboot after data turn on

[FiQ75]

S5 sm-g900f (6.0.1)
AP G900FXXS1CQDB
CP G900FXXU1CQAQ
CSCG900FOLB1CPH1
MALAYSIA XME

hi..my s5 also had a random reboot but when i turn on data connection..takes about a minute lagg..then black screen..and suddenly ask for back up pincode coz restating can't use finger print..have been hard reset it then..problems occurs a couple of weeks after installing all my apps..dunno why the causes..is it the apps or what..using 64GB SD CARD..
Need assistance

 

[Rukbat]

It could be one of many things. Have you tried bring it into your carrier and asking them for help?

Or you could start in Safe Mode (see https://support.t-mobile.com/docs/DOC-28456 ) to see if it's an app causing it. If it works in safe mode, run one app at a time to see which one causes the problem.