External Keyboard problemsCheck the keyboard cable — Shut down the computer. Disconnect the keyboard cable and check it for damage, and firmly reconnect the cable.If you are using a keyboard extension cable, disconnect it and connect the keyboard directly to the computer.Check the external keyboard —1. Shut down the computer, wait 1 minute, and turn it on again.2. Verify that the numbers, capitals, and scroll lock lights on the keyboard blink during the boot routine.3. From the Windows desktop, click the Start button, point to Programs, point to Accessories, and click Notepad.4. Type some characters on the external keyboard and verify that they appear on the display.If you cannot verify these steps, you may have a defective external keyboard.To verify that the problem is with the external keyboard, check the integrated keyboard —1. Shut down the computer.2. Disconnect the external keyboard.3. Turn on the computer.4. From the Windows desktop, click the Start button, point to Programs, point to Accessories, and click Notepad.5. Type some characters on the internal keyboard and verify that they appear on the display.If the characters appear now but did not with the external keyboard, you may have a defective external keyboard. Contact Dell (see Contacting Dell).Run the keyboard diagnostics tests — Run the PC-AT Compatible Keyboards tests in the Dell Diagnostics (see Dell Diagnostics). If the tests indicate adefective external keyboard, contact Dell (see Contacting Dell).Unexpected charactersDisable the numeric keypad — Press to disable the numeric keypad if numbers are displayed instead of letters. Verify that the numbers lock light isnot lit.Lockups and Software ProblemsThe computer does not start upEnsure that the AC adapter is firmly connected to the computer and to the electrical outlet.The computer stops respondingNOTE: Use the integrated keyboard when running Dell Diagnostics or the system setup program.NOTE: When you attach an external keyboard to the computer, the integrated keyboard remains fully functional.CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.NOTICE: You might lose data if you are unable to perform an operating system shutdown.