AC DC wall adapter question: HELP

hello all im not that savvy on electrical stuff when it involves adapters we have a water softener unit for the house and i believe the adapter has gone bad, not sure how to test if its bad or its the actual circuit board thats gone bad. the picture attached is the adapter, i also have many adapters from other devices that work and was wondering if i need an exact match when it comes to the input and output info on the adapter or what am i looking for exactly not to burn the board. any help would be super awesome. and thanks alot