Solution
1. Press [Menu].
2. Press [Left cursor] or [Right cursor] to select [2.COMMON SETTINGS], then press [Set] ([OK]).
3. Press [Left cursor] or [Right cursor] to select [5.TONER SAVER MODE], then press [Set] ([OK]).
4. Press [Left cursor] or [Right cursor] to select [OFF], then press [Set] ([OK]).
5. Press [Stop/Reset] to return to standby mode.