What is a common issue that may prevent a computer from powering on?

Power issues are among the most common reasons a computer may fail to power on. This can include problems such as a faulty power supply unit (PSU), a loose or damaged power cable, or issues with the power outlet itself. When a computer does not receive the necessary electrical power, no components will function, and the system will remain unresponsive, which could be mistaken for a more complex issue. Diagnosing power issues often involves checking the connections and testing the power source, which is a fundamental troubleshooting step in computer maintenance.

In contrast, a faulty operating system, incompatible software, or corrupted files generally affect the functioning of a system that is already powered on. These issues can lead to boot failures or crashes after the power-on self-test (POST) is completed, but they do not typically prevent a computer from powering on in the first place. Therefore, when troubleshooting a non-responsive computer, focusing on power issues is crucial.