Root [T-Mobile] Factory Reset

[mach1monorail]

Is factory resetting this phone dangerous once rooted? I'm having issues connecting to 4G/everything but Wifi and after troubleshooting, T-Mobile suggested I reset.

 

[GTWalling]

Just make sure you backup before you reset using Samsung Kies connected via USB.

 

[valiant1940]

Backing up on kies didn't backup all my contacts

 

[GTWalling]

Your contacts should have been backed up by Google using your G-Mail address.