• TDS1102B Self Calibration Failure

    When I run Self Calibration  on TDS1102B, it fails at Step 1. If the selfcalibration fails at step 1 could any one help what it indicates (Bad reference voltage  ?). I am interested in knowing the possible rootcauses for this failure. Whether self calibration error could be corrected just by doing the factory calibration ? OR does the oscilloscope needs any hardware repair ?