Dell Precision T3400 User's Guide - Page 144

lower-right corner of the Start menu as shown below, and then click Shut Down. The computer turns off after the operating system shutdown process is complete. 2 Ensure that the computer and all attached devices are turned off. If your computer and attached devices did not automatically turn off when you shut down your operating system, press and hold the power button for about 4 seconds to turn them off. Before Working Inside Your Computer Use the following safety guidelines to help protect your computer from potential damage and to help to ensure your own personal safety. CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide. NOTICE: Handle components and cards with care. Do not touch the components or contacts on a card. Hold a card by its edges or by its metal mounting bracket. Hold a component such as a processor by its edges, not by its pins. NOTICE: Only a certified service technician should perform repairs on your computer. Damage due to servicing that is not authorized by Dell is not covered by your warranty. NOTICE: When you disconnect a cable, pull on its connector or on its pull-tab, not on the cable itself. Some cables have connectors with locking tabs; if you are disconnecting this type of cable, press in on the locking tabs before you disconnect the cable. As you pull connectors apart, keep them evenly aligned to avoid bending any connector pins. Also, before you connect a cable, ensure that both connectors are correctly oriented and aligned. NOTICE: To avoid damaging the computer, perform the following steps before you begin working inside the computer. 1 Ensure that the work surface is flat and clean to prevent the computer cover from being scratched. 2 Turn off your computer (see "Turning Off Your Computer" on page 143). NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug the cable from the network device. 144 Adding and Replacing Parts