If there is power to the terminal block inside the electrical housing, then the Ballast is bad. There is a date on the underside of the ClearO3. If it is newer than 10/01/15 then the ballast is replaceable.  If it is older the complete ClearO3 must be replaced.
Note: the replacement lamp is still good and can be used for replacement after the 13,000-hour life span of the lamp in the new unit is over.