Hi Aussiebear. This link has the manual way to show hidden cells and some interesting VBA that you might want to trial....
How to show hidden data in Excel chart - Excel Off The Grid
HTH. DaveSub ToggleChartDisplayHiddenRows() 'Declare and assign variable Dim cht As Chart Set cht = ActiveChart 'Ignore errors if no chart active On Error Resume Next 'Toggle hidden data visibility cht.PlotVisibleOnly = Not cht.PlotVisibleOnly On Error GoTo 0 End Sub