Incase, you haven't done any settin changes to practice your hidden technical skills then,
First make sure you are gettin Satellite signals on your connection..
For 303 ( Channel search/Re-install service ) error..
Press Menu button (keep button pressed without leavin) till you get Advanced settings /Installation on screen..
Check Satellite, it should be SES8 for North & ST2 for South.. Select one as per your alignment if required..
Check Frequency parameters as per your given alignment are correct..
Navigate down to last and Press OK on Scan..
You can also send SMS For 303 error as 'DISHTV 303' and send it to 57575 from your RMN..