Here are some steps to fix Roku 2nd Generation remote inputs not responding issue-
# Remove the batteries from the remote.
# Look carefully into the battery compartment of the remote
# Unplug the power from the Roku
# Wait for 5 seconds.
# Connect the power back to the Roku.
# Wait for Roku banner to bounce around on the screen.
# Put the batteries back in the remote.
# Press and hold the purple button in the battery compartment of the remote for 5 seconds.
# Wait for the Roku to finish booting up