Hi RokuDanny-R ,
I bought a Roku-Sharp 50" TV. I used it for a while and I went on vacation for 2 weeks, on getting back the tv started rebooting when I put it on. It will only show sharp, go black and show sharp again. It went on and on. I pressed and held the start button for some minutes to reset it, it still did not work. I called sharp but they could not find my model. I tried to update firmware by downloading into a usb from tvupdate.roku.com but it asked for a roku model number (4 letters and a number). This number is not at the back of the tv, it can only be retrieved from 'about' in settings in the tv, so no way to get to the roku model number, I wonder why it was not on the TV. It also asked for a serial number and it stated that it will be 12 characters. The model number at the back of the TV does not work to update the firmware. My TV is 50'' , the model at the back is LC-50LB481C and the serial number is MAKH9YA000419 (13 characters). Can anyone assist with the roku model number? I called sharp, they could not even find my model. Is the tv now a garbage?