If you're having trouble like Brother Printer Offline, it's possible that the machine isn't turned on. Check to see if the machine wakes up from sleep mode. If it doesn't, double-check that it's plugged in and that any power switches are switched on.
This approach does not apply if you are unable to power on the system. To sort out this issue, go to Troubleshoot this hardware issue.
Further, look for any error warnings on the LCD. If the LCD displays an error, troubleshoot the error to resolve the problem.