What is a Bootloop, Soft-brick, or Hard-brick?
Bootloop is when your Android smartphone gets stuck on boot up, you might see a boot splash (such as Samsung/HTC/Motorla logo) or boot animation and your phone gets stuck there.
This is called “boot-loop” and your phone powers on but does not boot all the way and gets stuck. Also, bootloops are called “soft-bricks”.
Most “soft-bricks” or bootloops can be recovered by installing a new ROM or restoring ROM in custom recovery such as ClockworkMod Recovery. 99% of the time, soft-bricks are recoverable so it’s not a big deal.
However, “hard-bricks” are where your phone does not power on at all, no power. Some devices like HTC Evo 3D can also be unbricked during a hard-brick using unbricking software, usually this requires use of a Linux computer. However, for most Samsung devices, hard bricks are un-recoverable by the user unless he has a JTAG RIFF Box.
For JTAG repairs where you are hard-bricked and there’s no way to unbrick, you can refer to MobileTechVideos, who does most JTAG repairs for $50 to anywhere in the world plus shipping and handling.