A client's desktop computer is not powering on at all when the power button is pressed. There are no sounds, no lights, and no fans spinning. Which of the following is the BEST first step to troubleshoot this issue?
Replace the CMOS battery on the motherboard immediately.
Open the computer case and inspect the power supply unit (PSU) for any signs of damage.
Switch the voltage selector switch on the back of the power supply unit (PSU) and try again.
Check if the power outlet and cables are functioning by using them with another device.