<human>:  How do I troubleshoot my computer when it won't turn on?
<bot>: First, you should make sure that the power cord is securely plugged into the computer and into the wall. Next, check if the power supply is functioning correctly by looking for any lights or fans that might indicate that it is running. If that fails, you should disconnect any devices such as printers, scanners, and external hard drives to isolate the problem. Additionally, make sure that all cables are connected securely, including ones connected to a monitor. Finally, try resetting the BIOS, if possible, and then restarting the computer.