Formulat to populate a "modified (Date) cell" after a dropdown cell has been populated with "non bla

I am trying to populate a "modified (Date) cell with today's date and time stamp (date only needed) only after populating a dropdown cell with data (non-blank). I've tried NOT(ISBLANK), but to no avail. The dropdown cell is used as a status cell indicating i.e., "complete", "needs follow-up", etc. The modified (Date) cell will be used as a reference marker for further follow-up. Any help is appreciated. Thank you and thanks for the kind help a week or so ago which helped me solve another issue. Still trying to get my head wrapped around the formula syntax, logic, etc.