The problem, the big problem is the new touch display that is incompatible with KitKat!!!!
This has happened to me!!!
You do the following test to see if that happens to mobile or because something else. With the phone off, you have to remove the motherboard from the chassis. Then, through a rectangular hole that exist in the chassis, you can see the connector of the touch. You have to disconnect the flexible connector there.
Mounted the MoBo on the chassis. Gets the battery and turns on.
If the phone starts, no bootloop, and now goes to the screen of Android, this means that the problem is in the touch, which is not 100% compatible. If the phone is as it was before disconnecting the touch. means that the problem is caused by something else.