Lenovo T420 User Manual
4. While the computer is off, remove all sources of power and external hardware. Refer to the procedure in
“Replacing memory” on page 123 on how to remove and reseat the memory modules. Remove any
non-original memory module added to your computer. After removing the extra memory module and
reseating the original memory module, repeat step 2. If the computer still does not turn on, consult the
user's reference guide for other customer-replaceable components that are attached to your computer
non-original memory module added to your computer. After removing the extra memory module and
reseating the original memory module, repeat step 2. If the computer still does not turn on, consult the
user's reference guide for other customer-replaceable components that are attached to your computer
If the computer still does not start up, call the Customer Support Center and a Customer Support Specialist
will assist you.
will assist you.
Spills on the keyboard
With a mobile computer, there are increased chances of spilling liquids on the keyboard. Because most
liquids conduct electricity, liquid spilled on the keyboard could create numerous short circuits, potentially
causing irreparable damage to your computer.
liquids conduct electricity, liquid spilled on the keyboard could create numerous short circuits, potentially
causing irreparable damage to your computer.
If you spill something on your computer:
Attention: Be sure that no liquid creates a short circuit between you and the ac power adapter (if in use).
Although you might lose some data or work by turning off the computer immediately, leaving the computer
on might make your computer unusable.
Although you might lose some data or work by turning off the computer immediately, leaving the computer
on might make your computer unusable.
1. Carefully unplug the ac power adapter immediately.
2. Turn off the computer immediately. If the computer does not turn off, remove the battery. The more
quickly you stop the current from passing through the computer the more likely you will reduce damage
from short circuits.
from short circuits.
3. Wait until you are certain that all the liquid is dry before turning on your computer.
Note: If you want to replace your keyboard, you can purchase a new one.
Error messages
• Message: 0176: System Security - The System has been tampered with.
Solution: This message is displayed if you remove the Security Chip and reinstall it, or install a new one.
To clear the error, enter the ThinkPad Setup. If this does not solve the problem, have the computer
serviced.
To clear the error, enter the ThinkPad Setup. If this does not solve the problem, have the computer
serviced.
• Message: 0177: Bad SVP data, stop POST task.
Solution: Checksum of the supervisor password in the EEPROM is not correct. The system board
should be replaced. Have the computer serviced.
should be replaced. Have the computer serviced.
• Message: 0182: Bad CRC of Security Settings in EEPROM. Enter ThinkPad Setup.
Solution: Checksum of the Security settings in the EEPROM is not correct. Enter ThinkPad Setup to
check Security settings, Press F10 and then press Enter to restart the system. If you still have a problem,
have the computer serviced.
check Security settings, Press F10 and then press Enter to restart the system. If you still have a problem,
have the computer serviced.
• Message: 0183: Bad CRC of Security Settings in EFI Variable. Enter ThinkPad Setup.
Solution: Checksum of the Security settings in the EFI Variable is not correct. Enter ThinkPad Setup
to check Security settings, Press F10 and then press Enter to restart the system. If you still have a
problem, have the computer serviced.
to check Security settings, Press F10 and then press Enter to restart the system. If you still have a
problem, have the computer serviced.
• Message: 0187: EAIA data access error
Solution: The access to EEPROM is failed. Have the computer serviced.
• Message: 0188: Invalid RFID Serialization Information Area
Chapter 10
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Troubleshooting computer problems
203