Troubleshooting Your Computer 3-17and press . Does MS-DOS display theroot directory contents for drive D?Yes. You may have a corrupted boot sector or fileallocation table (FAT) on drive C. Go to step 9.No. Go to step 8.6. Rename your autoexec.bat and config.sys files,remove the operating system diskette fromdrive A, and reboot the computer. Does the oper-ating system load now?Yes. You have an error in your autoexec.bat orconfig.sys file. Use a text editor to examine thecontents of these files and locate the error. For infor-mation on the correct syntax for commands in thesefiles, see the documentation that accompanied youroperating system.No. Go to step 7.7. Insert your diagnostics diskette into drive A, andreboot the computer. Then run the Hard-DiskDrives (Non-SCSI) test group. Does your drivepass all the tests?Yes. Go to step 8.No. Go to step 9.8. Replace your diagnostics diskette with the operat-ing system diskette, and reboot the computer.Does the operating system load now?Yes. The hard-disk drive may contain a corruptedoperating system or it may have bad sectors. Re-install the operating system as described in thedocumentation that came with it. If reinstalling theoperating system does not correct the problem, go tostep 9.No. Go to step 9.9. Call Dell for technical assistance.See Chapter 5, “Getting Help,” for instructions.Troubleshooting an External KeyboardWhen you attach an external keyboard, the built-in key-board remains fully functional except for the embeddednumeric keypad. During POST, the computer checkswhether an external keyboard is connected; if it is, thecomputer recognizes both the built-in keyboard and theexternal keyboard. If an attached external keyboard doesnot work when you boot the computer, make a copy ofthe Diagnostics Checklist found in Chapter 5 and fill itout as you complete the following procedure:1. Turn off the computer, and then remove the key-board cable and check it for bent pins.2. Reboot the computer.3. Make sure the cable from the external keyboardis firmly connected to the keyboard/mouse con-nector on the back of the computer. (See“Checking Connections” found earlier in thischapter.)4. If you are using a keyboard that can be config-ured with various switch settings, make sure theswitch is set to PS/2, Enhanced XT/AT, or PC/AT.The switch settings are usually on the bottom of thekeyboard, sometimes behind a panel tab.5. Turn off the computer, wait one minute, and thenturn it on again. During the boot routine, do theNum Lock, Caps Lock, and Scroll Lock indicatorson the external keyboard blink momentarily?Yes. Go to step 6.No. You may have a defective keyboard. Go tostep 9.6. Does the computer recognize the externalkeyboard?Use the external keyboard to type some characters.Do they appear on the display?Yes. The problem is resolved.No. Go to step 7.55899BK1.BK : 55899c31.fm Page 17 Wednesday, February 4, 1998 1:20 PM
