Splash screen offered tour of 10.5 and promptly froze. Could not select tour or cancel. Had to reboot. Now device does not recognize microSD card. Reinstalling card does not help. Asks to format but gets stuck in an endless menu loop. Restart does not help.
For those Roku models that have SD card slots, a corrupted card can prevent the Roku from advancing beyond the startup screen when powering up. Try removing the SD card and restarting.
You may be able to salvage the card. Try formatting the card in your computer, if it has a card reader that can handle SD cards. After formatting, see if the Roku will detect and reformat the card successfully.