What should be checked if an electrofisher has stopped working and shows no display or tone?

In the scenario where an electrofisher has stopped working and shows no display or tone, checking the battery cover interlock and battery connection is crucial. The battery cover interlock ensures that the system is securely closed and operational. If the cover is not properly engaged, it can prevent the device from functioning. Additionally, the battery connection itself is vital; if the battery is loose, discharged, or not making proper contact, the equipment will not receive power, leading to the absence of display or tone.

This focus on battery issues is particularly relevant because power supply problems are often the most common reasons for failure in electronic devices. Ensuring that the battery is correctly installed and that there is a good electrical connection can resolve many basic operational issues. Other options, while potentially important in different circumstances, do not directly address the immediate power and operational integrity of the electrofisher.