•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 modification.

•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 modified 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 configurations 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.

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Lenovo L421, L520, L420 manual Checkout guide, Diagnostics using PC-Doctor for DOS
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L420, L520, L421 specifications

The Lenovo L421, L520, and L420 are part of Lenovo's ThinkPad series, which is known for its reliability, durability, and performance. These models are designed primarily for business professionals and students, providing a blend of functionality and portability tailored for everyday computing.

The Lenovo L421 is equipped with the second-generation Intel Core processors, which enhance its performance and efficiency. It features a 14-inch LED backlit display, offering sharp visuals and sufficient screen real estate for multitasking. The L421 also sports a spill-resistant keyboard, ensuring that accidental spills do not affect the device's functionality. This model supports up to 8GB of RAM and incorporates various connectivity options, including USB 3.0 ports, HDMI, and an SD card reader, which makes it versatile for various peripherals.

The L520 is another solid offering from Lenovo, featuring a slightly larger 15.6-inch display for increased productivity. It shares many characteristics with the L421, such as the use of Intel’s second-generation processors. The L520 also emphasizes security with features like a fingerprint reader and a Trusted Platform Module (TPM) for data encryption, appealing to businesses that require stringent security measures. Its ExpressCard and docking station compatibility add flexibility, allowing users to tailor their setups according to their needs.

The L420, like its siblings, comes with an emphasis on performance and utility. With a 14-inch HD display, it offers vibrant visuals. The L420 also benefits from Lenovo's legendary keyboard design, which ensures a comfortable typing experience. This model is geared for users who require a balance between performance and portability without compromising on essential features. The same Intel Core processors and security features are incorporated, ensuring a reliable experience for professional applications.

All three models feature Lenovo's innovative Power Management technology, which optimizes battery life, allowing users to work longer hours without needing to recharge. Additionally, they are built with robust materials that ensure longevity, making them suitable for both office and on-the-go environments.

Overall, the Lenovo L421, L420, and L520 exemplify the ThinkPad series' commitment to performance, security, and durability, making them excellent choices for anyone looking for reliable laptops for professional use.
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