I have an Toshiba 46LX177 which quit working last Thursday, 7/8. I tried the SD card repair method with a 1 GB Sandisk SD card and a 8 GB Sandisk SD card. Both didn't work. For the heck of it, I found a 512MB Sandisk SD card on Ebay for $10 and purchased it.
Received the SD card today, 7/15 and checked to be sure it was formatted FAT. Followed the instructions to unzip the download and copy those files to the 512MB Sandisk SD card. Unplugged the lcd, removed the service cover, inserted the card, plugged back in the lcd. The light flashed yellow a couple of times and then went green and yellow. Unplugged the power cord, removed the 512MB Sandisk and then plugged back in the power cord. Push the button on the LCD and everything is back to normal. I guess that new 4K led will have to wait.
Thank you guys for the repair info.