My issue is similar to Displaying X, Y coordinates on ArcGIS not working but the solution there did not work for me.
I am importing Excel data into ArcMap, and have already saved it as a CSV. When I Display X, Y Data... from the dropdown list, it shows the points at "0,0" on the map. When I change the projection from the WGS84 to Africa_Albers_Equal_Area_Conic, it shifts the points to center on the African continent.
When I brought the CSV into ArcMap, it converted my formatting of decimal degrees (correctly, I believe) and then I padded them with zeroes as that seemed to be other peoples problems (pictures).