If I reflash firmware do I lose my data?

[umby75fg]

Hi, my friend's phone doesn't load the OS anymore.
When he turn on the phone his phone is stuck on Samsung logo.
I know that if you try to reflash OS through Odin you can have high chances to restart the phone with its old programs and data.
But someone said him that he's forced to delete all software and data.
What do you think?
Any help is a welcome!

 

[Itsa_Me_Mario]

Reflashing firmware always deletes data unless you modify the image to treat it as an OTA.

 

[umby75fg]

Do I remember wrong? I remember the opposite with my old S3 or S4 phones..

 

[ironass]

Providing that you are flashing the stock Samsung firmware for the correct model version of Galaxy S5, (there are 42 different S5 models), and Samsung Product Code, there should be no issue with updating or re-flashing the firmware via Odin.

However, as with all flashing procedures, it is strongly suggested that a backup is made... just in case.