The guide has locked up. Neither the buttons on the remote, nor the buttons on the converter itself work.

Try unplugging the converter and then plugging it back in.  This will reset the converter and allow for data to be downloaded.  It will take some time for all the guide information to re-load.  If there is still a problem after the information has appeared, contact your local office at 877.955.SECV or chat us live for further assistance.