Lenovo 20AQ004JUS, 20AQ006HUS manual Memory module problems, Networking problems, Ethernet problems

Table 7. Beep errors (continued)

Problem	Solution
Four cycles of four short beeps	Shut down the computer immediately and have the
	computer serviced.
Five short beeps	The system board has a problem. Have the computer
	serviced.

Memory module problems

Print these instructions now and keep the instructions with your computer for reference later.

If your memory module is not operating properly, check the following items:

1.Verify that the memory module is installed and seated correctly in your computer.

It might be necessary to remove all added memory modules to test the computer with only the factory-installed memory modules, and then reinstall the memory module one at a time to ensure a proper connection.

2.Check for error messages during startup.

Follow the appropriate corrective actions for power-on self-test (POST). See “Error messages” on page 124.

3.Verify that the latest UEFI for your model has been installed.

4.Verify the proper memory configuration and compatibility including the maximum memory size and the memory speed.

5.Run diagnostic programs. See “Diagnosing problems” on page 123.

Networking problems

The following are the most common networking problems.

Ethernet problems

•Problem: The computer cannot connect to the network.

Solution: Make sure that:

–The cable is installed correctly.

The network cable must be securely connected both to the Ethernet connector of your computer and to 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.

–You are using the correct device driver. To install the correct driver, do the following:

1.Open Control Panel and click Hardware and Sound ➙ Device Manager. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

2.If the exclamation mark ! is displayed next to the adapter name under Network adapters, you might not be using the correct driver or the driver might have been disabled. To update the driver, right-click the highlighted adapter.

3.Click Update Driver Software, and then follow the instructions on the screen.

–The switch port and the adapter have the same duplex setting.

If you configured the adapter for full duplex, make sure that the switch port also is configured for full duplex. Setting wrong duplex mode can degrade performance, cause data loss, or result in lost connections.

Chapter 10. Troubleshooting computer problems 127