There are several possibilities depending on the application. For TDRapplications where the internal clock is used, Autoset does not know where the correct time base setting is, so it does nothing. Another possibility is that trigger setup is incorrect. Some examples are that the wrong trigger source is selected. For Clock Recovery, one thing to check is to insure that the correct data rate is selected. For products with SW version 2.0 and higher, the Define Autoset (in the Utilities menu) function may need to be set. For example, for NRZ-format signals, NRZ Eye (in the Define Autoset window) would be the correct setting.