External Monitor Problems - Lenovo thinkpad L450 User Manual

Solution: Press and hold the power button for four seconds or more to turn off your computer; then
turn it on again.
• Problem: Missing, discolored, or bright dots appear on the screen every time you turn on your computer.
Solution: This is an intrinsic characteristic of the TFT technology. Your computer display contains
multiple thin-film transistors (TFTs). A small number of missing, discolored, or bright dots on the screen
might exist all the time.

External monitor problems

• Problem: The external monitor is blank.
Solution: To bring up the image, press the display-mode switching key
monitor. If the problem persists, do the following:
1. Connect the external monitor to another computer to make sure that it works.
2. Reconnect the external monitor to your computer.
3. Refer to the manual shipped with the external monitor to check the resolutions and refresh rates that
are supported.
– If the external monitor supports the same resolution as the computer display or a higher resolution,
view output on the external monitor or on both the external monitor and the computer display.
– If the external monitor supports a lower resolution than the computer display, view output on the
external monitor only. (If you view output on both the computer display and the external monitor,
the external monitor screen will be blank or distorted.)
• Problem: You cannot set a higher resolution than the present one on your external monitor.
Solution: Make sure that the monitor information is correct. Do the following:
1. Connect the external display to the monitor connector, and then connect the monitor to an electrical
outlet.
2. Turn on the external display and the computer.
3. Right-click on the desktop, and do one of the following:
– For Windows 7 and Windows 8.1: Click Screen resolution.
– For Windows 10: Click Display settings, show the displayed window in full screen, and then
click Advanced display settings.
Note: If your computer cannot detect the external monitor, click the Detect button.
4. Click the icon for the desired monitor (the Monitor-2 icon is for the external monitor).
5. Do one of the following:
– For Windows 7 and Windows 8.1: Click Advanced settings.
– For Windows 10: Click Display adapter properties.
6. Click the Adapter tab.
7. Make sure that the correct device driver name is shown in the adapter information window.
Note: The device driver name depends on the video chip that has been installed on your computer.
8. Click OK.
If the information is incorrect, reinstall the device driver.
– Check the monitor type and, if necessary, update the driver by doing the following:
1. Connect the external monitor to the monitor connector, and then connect the monitor to an
electrical outlet.
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and select the desired