Lenovo IdeaPad Y550P User Manual page 56

Chapter 5. Troubleshooting
If your computer is in sleep mode connect the AC adapter to the
computer, then press any key or the power button.
If your computer is in hibernation mode or power-off state. Connect
the AC adapter to the computer, then press the power button to
resume operation.
If the system still does not return from sleep mode, your system has
stopped responding, and you cannot turn off the computer; reset the
computer. Unsaved data may be lost. To reset the computer, press and
hold the power button for 4 seconds or more. If the computer is still not
reset, remove the AC adapter and the battery.
Computer screen problems
The screen is blank.
Do the following:
If you are using the AC adapter, or using the battery, and the battery
status indicator is on, press Fn + up arrow to make the screen brighter.
If the Power indicator is in blinking, press the power button to resume
from the sleep mode.
If the problem persist, follow do the Solution in the following problem
"The screen is unreadable or distorted."
Press Fn+F2 to confirm whether the LCD screen has been turned off.
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