Instruct: Classify a review into positive or negative sentiment.
Query: Not operational

When we opened the package to do the initial set-up the display remained blank, could not set any function. Turned over to see if there was a restrictor to be removed from the batttery and instead found one screw missing from the back. Opened to find the battery intact but still would not display. Upon reassemble a faint humming was heard that continued but yet still no display. Returned for full refund