How to Hard Reset Samsung Galaxy S5

force reset Reset the device: Press and hold for more than 7 seconds to reset the device if it has fatal errors or hang-ups or freezes.
Unlock Samsung Galaxy S5 using hard reset

SG S4 hard reset or reset Galaxy S4: PRESS AND HOLD VOLUME UP + Home Button + Power
or simply Volume UP + POWER ON
Turn the phone off

Press and hold VOLUME UP and HOME (middle) button
Press Power until the phone vibrates
Wait until you see the Android logo then release all buttons
Select Wipe data/Factory Reset with VOLUME DOWN, press Power (right hand-side)
Select Yes –delete all user data with Volume Down and then press Power
After format, press Power again to reboot Power. (select reboot system now)
unlock i9500 galaxy samsung cell phone red triangle exclamation mark
or Factory format entering SGS5 format code
Use this method to hard reet your Samsung Galaxy S5: Enter *2767*3855#. Warning!! All your data including contacts and messages will be lost! Copy all your necessary data/Contacts/Messages etc to SIM or make backup to your PC before full reset (Carbon backup is a good one)! Take out SIM card before full reset. This shouldn’t delete the data on your external SD card, but as a precaution, remove as well.
Note: If you reset your device to the factory defaults with SD card encryption setting enabled, the device will not be able to read your encrypted files. Disable this setting before resettling the device.
sgs5 firmware flash download mode: PRESS AND HOLD VOLUME down + Home Button + Power on
Warning! Perform at YOUR OWN risk.