if it has a broken top layer which has small gaps and things, it might not be extruding enough filament. Measure the diameter of filament and put into software under OTHER Tab, Filament Diameter = 1.750 mm.... Measure to make sure its 1.75 (or could be 3mm), if your filament measures 1.71 mm insert that into settings.
Also you can increase wall layer thickness from 2 layers to 3 or 4... I generally use 3-4 layers just to cover up any imperfections, sometimes if I dont measure the filament diameter proper or the right temps I can have a print that may have small holes or gaps in the top or side layers.
I would also like to see pics, it could be a number of other problems as well.