Method and device for replacement of a defective module is preferably within a digital exchange PBX

Different states of a module (BG) are displayed with the aid of at least one optical display element, e.g. in the form of a light-emitting diode (RL, GL), that has been visibly mounted on the module. By pressing a repair key (RT), a repair state is initiated in which the necessary actions and control procedures to shut down the faulty module take place. A new module inserted in a module frame (BR) is automatically recognized. A test function and an automatic start-up procedure of the new module depending on a positive test result are then activated.