Lenovo L420 Laptop User Manual


 
Scratched (cosmetic) parts
Distortion, deformation, or discoloration of the cosmetic parts
Plastic parts, latches, pins, or connectors that have been cracked or broken by excessive force
Damage caused by liquid spilled into the system
Damage caused by the improper insertion of a PC Card or the installation of an incompatible card
Improper disc insertion or use of an optical drive
Diskette drive damage caused by pressure on the diskette drive cover, foreign material in the drive,
or the insertion of a diskette with multiple labels
Damaged or bent diskette eject button
Fuses blown by attachment of a nonsupported device
Forgotten computer password (making the computer unusable)
Sticky keys caused by spilling a liquid onto the keyboard
Use of an incorrect ac power adapter on laptop products
The following symptoms might indicate damage caused by nonwarranted activities:
Missing parts might be a symptom of unauthorized service or modication.
If the spindle of a hard disk drive becomes noisy, it may have been subjected to excessive force,
or dropped.
Checkout guide
Use the following procedures as a guide in identifying and correcting problems with the ThinkPad Notebook.
Note: The diagnostic tests are intended to test only ThinkPad products. The use of non-ThinkPad products,
prototype cards, or modied options can lead to false indications of errors and invalid system responses.
1. Identify the failing symptoms in as much detail as possible.
2. Verify the symptoms. Try to re-create the failure by running the diagnostic test or by repeating the
operation.
Diagnostics using PC-Doctor for DOS
The ThinkPad Notebook has a test program called PC-Doctor for DOS (hereafter called PC-Doctor.) You can
detect errors by running the diagnostics test included in PC-Doctor.
Note: PC-Doctor for DOS is available at the following Web site:
http://www.lenovo.com/support
To create the PC-Doctor diagnostic CD, follow the instructions on the Web site.
For some possible congurations of the computer, PC-Doctor might not run correctly. To avoid this problem,
you need to initialize the computer setup by use of the BIOS Setup Utility before you run PC-Doctor.
To enter BIOS Setup Utility, do as follows:
1. Turn on the computer.
2. When the ThinkPad logo comes up, immediately press F1 to enter the BIOS Setup Utility.
Note: If a supervisor password has been set by the customer, BIOS Setup Utility menu appears after the
password is entered. You can start the utility by pressing Enter instead of entering the supervisor password;
however, you cannot change the parameters that are protected by the supervisor password.
On the BIOS Setup Utility screen, press F9, Enter, F10, and then Enter.
30 Hardware Maintenance Manual