Faults in AOV control panels can occur for several reasons, with the most common being a battery issue. In order to try to identify the source of the fault, firstly check the conditions of the battery and if the control panel is providing an output and operating correctly.
If the control panel is providing an output, then the fault is likely to be with one of the AOV window actuators linked to the AOV panel.
If connected to a fire alarm system, check to ensure the fault isn’t present on this system as that can cause interface issues with the AOV control panel.