Beep Errors; Memory Problems; Modem And Networking - Lenovo ThinkPad T420 User Manual

If the problem persists, have the computer serviced.
• Problem: My screen goes blank while the computer is on.
Solution: Your screen saver or power management may be enabled. Do either of the following:
– Touch the TrackPoint or the touch pad, or press a key to exit the screen saver.
– Press the power switch to resume from sleep (standby) or hibernation.

Beep errors

Table 11. Beep errors
Problem
One short beep, pause, three short beeps, pause, three
more short beeps, and one short beep
One long and two short beeps
Four cycles of four short beeps
Five beeps

Memory problems

Print these instructions now and keep it with your computer for reference later.
If your memory is not operating properly, check the following items:
1. Verify that the memory is installed and seated correctly in your computer.
It may be necessary to remove all added memories to test the computer with only the factory-installed
memories, and then reinstall the memory one at a time to ensure a proper connection. For the
procedures to remove and reinstall a memory, refer to "Replacing memory" on page 123.
2. Check for error messages during startup.
Follow the appropriate corrective actions for Power-on self-test (POST) "Error messages" on page 204.
3. Verify that the latest system BIOS (UEF BIOSI)for your model has been installed.
4. Verify the proper memory configuration and compatibility including the maximum memory size and the
memory speed.
For details, refer to the instructions in "Replacing memory" on page 123.
5. Run "Lenovo ThinkVantage Toolbox" on page 203.

Modem and networking

The following are the most common modem and networking problems:
Modem problems
• Problem: Your modem application does not work with the built-in modem.
Solution: Make sure that the internal modem port is enabled by opening the Device Manager and doing
as follows:
For Windows 7 and Windows Vista:
1. Click Start.
208
User Guide
Solution
Make sure that memory modules are installed correctly. If
they are, and you still hear the beeps, have the computer
serviced.
The video function has a problem. Have the computer
serviced.
The Security Chip has a problem. Have the computer
serviced.
The system board has a problem. Have the computer
serviced.