This problem may show up on other Sharp models including  LC-55LE653U, LC-65LE664U, LC-70LE733U, LC-60LE660U and LC-70LE660U.

Though research indicates main board replacement will fix this problem, it would be cheaper and easier to reload the firmware since it appears to be corrupted and stuck during the boot process.

Steps are as follows.

1. Search for and download the latest firmware from Sharp.  For LC-60LE664U, the file is here.
2. Extract the .img file from the archive
3. Plug in and format a USB drive FAT32
4. Copy the .img file onto the root directory of your USB drive and rename the file install.img
5. Have your TV unplugged and insert the USB drive into the side USB port and plug the TV in.
6. The firmware should install.  Once finished, remove the USB drive, unplug the TV and plug it back in.