having problems with updating my galaxy s5 version.

[AC Question]

hey i have a galaxy s5 (sm-g900f) and its on version 4.4.2.
i really want to upgrade this device to the latest version and im having some diffculties
the first and main one is that i cant connect it to the computer, ive tried literally everything, the computer just says the the device cannot be detected.
second one is that my phone shows me all the time that the system is up to date i dont know why. any help with upgrading the phone? perhaps without using pc or anything im really out of options here thank you!

 

[Rukbat]

If here's no update showing when you try to update (in About device/Software update), there's no update. Unless it was locked to a carrier, it'll eventually come from Samsung.