Find a duplicate in a column.

[SinKoh]

Basically I have a list of part sales with the previous years sales numbers in each row. Sometimes a customer orders the same part two different times causing it to show up on the excel report twice. This is a problem because it is causing the 2017, 2016, etc data to show up twice as well. When this is turned into pivot table I have incorrect data because of the duplication. Is there a way in VBA after the sheet is populated to cycle through the part name column and if a part exists more than once set a specific range of cells to 0?
In the image below you see one part is duplicated three times. For the second and third on I need to set 2017 qty and to the right to 0.

https://imgur.com/a/Dw2CTDu

 

[shknbk2]

Based on your picture and description, this is what I came up with:

Sub findDuplicates()
    Dim r As Long
    
    For r = 2 To Cells(Rows.Count, 1).End(xlUp).Row
        If Application.WorksheetFunction.CountIf(Range("A1:A" & r - 1), Cells(r, 1).Value) > 0 Then
            Range(Cells(r, 7), Cells(r, 9)).Value = 0
        End If
    Next r
End Sub