Nothing on the lower screen, not even the device model identification and copyright info means it's not getting very far into the boot process until it borks and restarts. So it's not loading any files at all, strongly indicative of either a firmware corruption or flash chip failure. If it's bad firmware then a successful re-flash of original fw should restore it. Did you get a "Success" message from Updater after the last flash? If so it might be a bad chip. If you got an error message then the flash didn't complete of course, but don't be put off by that and try again over and over until you get a completed flash with success message. As said, bootlooping devices can be a pain to flash but once a flash does initiate it should hold and finish. The window of time to catch the flash is limited to the period when 'System' is bouncing around on the screen, mere seconds. Persistence will pay off if this is a software bricking. Try this technique:
  1. Use a REAR USB2 port of a desktop PC if available, not a front or USB3 port, have the cable plugged into the PC before you start.
  2. Ensure the device is fully off.
  3. Load the firmware RGN file into Updater and select the radio button for 'USB Device' on the GUI.
  4. Position your mouse cursor over the GUI's 'OK' button to be ready.
  5. Hold the screen with your thumb and plug in the USB cable into the device, that should power it on and let it enter preboot so immediately shift your attention back to Updater's GUI.
  6. The very instant you see the device details appear in the window next to USB Device, click the OK button or just hit the Enter key on the PC keyboard.
  7. Keep holding the device's screen firmly until the flash either finises or fails.
If it fails then start all over, again ensuring it's fully off.