Dell ChengMing 3980, Service Manual, Page: 4 / 79

3 Turn off your computer.
4 Disconnect all the network cables from the computer.
CAUTION: To disconnect a network cable, first unplug the cable from your computer and then unplug the cable from the
network device.
5 Disconnect your computer and all attached devices from the electrical outlets.
6 Press and hold the power button while the computer is unplugged to ground the system board.
NOTE: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically touching an
unpainted metal surface at the same time as touching a connector on the back of the computer.
After working inside your computer
After you complete any replacement procedure, ensure that you connect any external devices, cards, and cables before turning on your
computer.
1 Connect any telephone or network cables to your computer.
CAUTION: To connect a network cable, first plug the cable into the network device and then plug it into the
computer.
2 Connect your computer and all attached devices to their electrical outlets.
3 Turn on your computer.
4 If required, verify that the computer works correctly by running ePSA diagnostics .
4 Working on your computer