What are the potential causes of a power failure *during* printer operation (if applicable) and how does that relate to it not turning on?

If the printer experienced a power failure while printing, it could have caused internal damage or a system lockup. The printer might then fail to power on. Check for any error messages on the display (if any). Try a full power cycle (unplug for 5 minutes, then plug back in). In more severe cases, internal components may need to be inspected and possibly replaced.