You might face a situation where the display on the keybox does not light up and is not responding to any input from the keypad.
Solution: You need to open the service door on the keybox and disconnect the battery backup cable from the PCB and then connect it again. (the braded multi colored cable) See installation guild for Keybox for a PCB schematics if you need to. Make sure to set date and time when the cabinet starts up if needed.
If this has happened once or twice it is probably nothing to worry about, the signal from the keypad to the display has been distorted temporarily, it can be enough with a static discharge when you are to input your pin code.
But is this happening several times a month, there is a possibility that the signal is being interrupted from a close by source, either some other electric component or appliance close to the cabinet, or from a faulty component on the PCB itself.
If there are no other electronics close by or cables that are running behind or close to the cabinet you might want to consider changing the PCB itself.
