In order for a survey to synchronize to the PDA / Laptop you should make sure of the following:
1. The survey is saved.
2. The survey is either in Test or Production mode
Surveys need to be in either Test or Production mode in order to get synchronized to the PDA.
5. The survey is assigned to the user on the PDA
If you are logging in with a different user to the PDA and a different user to the Designer, make sure you have assigned the survey to the correct user by clicking the “Survey > Assign to Surveyors” menu option of the designer: