You do not need to diagnose the system before calling. It is helpful to know whether the keypad lights up or makes a sound, whether remotes or other controls still operate the gate, and whether the change followed a storm, outage, code change, landscaping work, or equipment replacement. A clear photo of the keypad and visible equipment labels can also help identify the setup.
For a wireless keypad, replacing a clearly weak battery is reasonable when the manufacturer identifies a user-serviceable battery compartment. For a hardwired keypad, it is best to leave cables, relays, terminals, and operator enclosures alone. Do not erase receiver memory, bypass a safety device, change force settings, or force a gate through a fault. Those shortcuts can turn a focused keypad concern into an entrance-wide problem.
If the gate is stuck open, stuck closed, or moving unpredictably, keep the travel path clear and mention how the problem affects access to the property. The best repair starts with the symptoms you can safely see, then checks the equipment behind them.