Troubleshooting – Lenovo M50-70 Notebook User Manual
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Chapter 4. Troubleshooting
21
Troubleshooting
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Display problems
When I turn on the 
computer, nothing appears 
on the screen.
• If the screen is blank, make sure that:
- The AC power adapter is connected to the computer, and
the power cord is plugged into a working electrical outlet.
- The computer power is on. (Press the Power button again
for confirmation.)
- The memory is installed correctly.
• If these items are properly set, and the screen remains blank,
have the computer serviced.
When I turn on the 
computer, only a white 
cursor appears on a 
blank screen.
• Restore backed-up files to your Windows environment or the
entire contents of your hard disk to its original factory 
contents using the Lenovo OneKey Recovery System. If you 
still see only the cursor on the screen, have the computer 
serviced.
The screen goes blank 
while the computer is on.
• Your screen saver or power management may be enabled. Do
one of the following to exit from the screen saver or to 
resume from sleep mode:
- Touch the touchpad.
- Press any key on the keyboard.
- Press the Power button.
- Press F9 (
) to confirm whether the backlight of the
LCD screen has been turned off.
BIOS password problems
I forgot my password.
• If you forget your user password, ask the system
administrator to clear your user password.
• If you forget your hard disk drive password, a Lenovo
authorized servicer cannot reset your password or recover 
data from the hard disk. You must take your computer to a 
Lenovo authorized servicer or a marketing representative to 
have the hard disk drive replaced. Proof of purchase is 
required, and a fee will be charged for parts and service.
• If you forget your administrator password, a Lenovo
authorized servicer cannot reset your password. You must 
take your computer to a Lenovo authorized servicer or a 
marketing representative to have the system board replaced. 
Proof of purchase is required, and a fee will be charged for 
parts and service.
