On the Windows 8 or Windows 8.1 operating system, open Control Panel and click Hardware and
Sound ➙ Adjust screen resolution ➙ Advanced Settings. Then click the Monitor tab and select a
new refresh rate.
• See your operating system documentation or help for further information on monitor settings.
If these actions do not correct the problem, your monitor might need service. See “Lenovo Support Web
site” on page 31 for details.
The image is discolored
Symptom: The image is discolored.
Action: The monitor might be affected by interference from nearby equipment. Magnetic elds around other
devices, such as transformers, appliances, uorescent lights, and other monitors might be causing the
problem. Move uorescent desk lighting or any equipment that produces magnetic elds further away from
the monitor. If this does not correct the problem, do the following:
1. Turn off the monitor. (Moving a color monitor while it is turned on might cause screen discoloration.)
2. Adjust the placement of the monitor and other devices so that they are at least 305 mm (12 inches) apart.
3. Turn on the monitor.
If these actions do not correct the problem, your monitor might need service. See “Lenovo Support Web
site” on page 31 for details.
Networking problems
The following are the most common networking problems. Select your networking problem from the
following list:
• “Ethernet problems” on page 46
• “A wireless LAN problem” on page 48
• “A wireless WAN problem” on page 48
• “Bluetooth problem” on page 48
Ethernet problems
For Ethernet problems, select your symptom from the following list:
• “Your computer cannot connect to the network” on page 46
• “The adapter stops working for no apparent reason” on page 47
• “If your computer is a Gigabit Ethernet model and you use a speed of 1000 Mbps, the connection fails
or errors occur” on page 47
• “If your computer is a Gigabit Ethernet model, it cannot connect to the network at 1000 Mbps. Instead,
it connects at 100 Mbps” on page 48
Your computer cannot connect to the network
Symptom: Your computer cannot connect to the network.
Actions: Ensure that:
• The cable is installed properly.
The network cable must be securely connected to both the Ethernet connector of your computer and
the RJ45 connector of the hub. The maximum allowable distance from the computer to hub is 100
meters. If the cable is connected and the distance is within acceptable limits but the problem persists, try
a different cable.
46 ThinkCentre E73z Hardware Maintenance Manual