VBA code to select filter value from drop down menu on one sheet and apply filter in a table on another worksheet - Excel 2010

Question

Very novice, trying to write a VBA code in EXcel 2010 to select filter value from a drop down list located in cell A1 of Sheet1 and apply filter value on column 4 of a data range A7:S1000 located on Sheet2. Below is the code, inserted in Sheet1, that I am using, but returning nothing. Where am I getting it wrong? Thanks aa lot.

Private Sub Worksheet_Change(ByVal Target As Range)
    ' Cell with dropdown where value to be selected
    Const DropDown = "a1"
    ' Sheet with data range to apply filter
    Const TableSheet = "Sheet2"
    ' Top left cell of the data range
    Const TableRange = "a7"
    If Not Intersect(Range(DropDown), Target) Is Nothing Then
        Application.EnableEvents = False
        If Range(DropDown).Value = "" Then
            Worksheets(TableSheet).ShowAllData
        Else
            Worksheets(TableSheet).Range(TableRange).AutoFilter _
                Field:=4, Criteria1:=Range(DropDown).Value
        End If
        Application.EnableEvents = True
    End If End Sub

Answer 1

@Scottyfrog I was hoping the advice I offered above in the comments would do the trick, but unfortunately it didn't. As an alternative, I rewrote your code in a way that was simpler for me to understand. I tested it on my own computer & it seems to work OK.

In addition, a possible cause of your problem could be that the filter couldn't find any values that matched your criteria. I've added a test to your code that will tell you if it can't find any values that match.

Let me know how it goes, and if it works, please uptick the answer.

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Range("A1"), Target) Is Nothing Then
 
    If Range("A1").Value = "" Then
        
    Worksheets("Sheet2").ShowAllData
    
    Else
    
        If Application.WorksheetFunction.CountIf(Worksheets("Sheet2").Range("D:D"), Range("A1")) = 0 Then
        
            MsgBox "The Filtered value doesn't exist in column D on sheet 2"
            
            Exit Sub
        
        End If
    
    Worksheets("Sheet2").Range("A7:S7").AutoFilter Field:=4, Criteria1:=Range("A1").Value
    
    End If
    
End If
  
End Sub