5 Troubleshooting126Hardware diagnostic testingThis section provides a more detailed approach to identifying ahardware problem and locating its source.Caution! Turn off devices before disconnecting cables: Beforedisconnecting any peripheral cables from the system, turn off thesystem and any external peripheral devices. Failure to do so cancause permanent damage to the system and/or the peripheraldevices.1 Turn off the system and all external peripheral devices. Disconnecteach of device from the system, except for the keyboard and thevideo monitor.2 Make sure the system power cord is plugged into a properlygrounded AC outlet.3 Make sure your video display monitor and keyboard are correctlyconnected to the system. Turn on the video monitor. Set itsbrightness and contrast controls to at least two thirds of theirmaximum ranges (see the documentation supplied with your videodisplay monitor).4 If the operating system normally loads from the hard disk drive,make sure there is no diskette in drive A and no CD-ROM disk inthe CD-ROM drive.5 If the power LED does light, attempt to boot from a floppydiskette or from a CD-ROM disk.6 Turn on the system. If the power LED does not light, see “Powerindicator does not light” on page 127.Verifying proper operation of key system lightsAs POST determines the system configuration, it tests for the presenceof each mass storage device installed in the system. As each device ischecked, its activity light should turn on briefly. Check for thefollowing:Does the diskette drive activity light turn on briefly? If not, see "FDDactivity indicator does not light." on page 127.
