On/Off error!!!

[Cornelius Thupi]

The device just switched off and when switching ON the screen just shows SAMSUNG flashing for hours and nothing happening, no response whatsoever?

 

[B. Diddy]

Welcome to Android Central! Probably either corrupt firmware or a hardware failure. Pull the battery to force a shutdown, then reinsert it and try booting into Recovery Mode: https://support.t-mobile.com/docs/DOC-27708. See if you can wipe the cache partition.