Private Sub SerialPort1_PinChanged(ByVal sender As Object, ByVal e As _
  System.IO.Ports.SerialPinChangedEventArgs) Handles SerialPort1.PinChanged
        'hier geht er nicht
        Timer1.Enabled = True
End Sub
 
Private Sub Button2_Click_1(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button2.Click
        'hier geht er
        Timer1.Enabled = True
End Sub