Paintwork
First I used putty to fix the imperfections, and then I sanded the entire cabinet:
Then I applied a layer of primer (MDF is quite absorbent):
And finally the cabinet is painted with black spray polyurethane paint:
Paintwork finished:
With the back covers placed:
By the way, we must recognize that the living room is not the best place for sanding and painting. But when you have no other place...