IBM 2621421 Hardware Maintenance Manual - Page 20

Reinstall all covers correctly before returning the machine to the customer. Electrical Safety Observe the following rules when working on electrical equipment. Important Use only approved tools and test equipment. Some hand tools have handles covered with a soft material that does not insulate you when working with live electrical currents. Many customers have, near their equipment, rubber floor mats that contain small conductive fibers to decrease electrostatic discharges. Do not use this type of mat to protect yourself from electrical shock. Find the room emergency power-off (EPO) switch, disconnecting switch, or electrical outlet. If an electrical accident occurs, you can then operate the switch or unplug the power cord quickly. Do not work alone under hazardous conditions or near equipment that has hazardous voltages. Disconnect all power before: - Performing a mechanical inspection - Working near power supplies - Removing or installing main units Before you start to work on the machine, unplug the power cord. If you cannot unplug it, ask the customer to power-off the wall box that supplies power to the machine and to lock the wall box in the off position. If you need to work on a machine that has exposed electrical circuits, observe the following precautions: - Ensure that another person, familiar with the power-off controls, is near you. Attention: Another person must be there to switch off the power, if necessary. - Use only one hand when working with powered-on electrical equipment; keep the other hand in your pocket or behind your back. Attention: There must be a complete circuit to cause electrical shock. By observing the above rule, you may prevent a current from passing through your body. - When using testers, set the controls correctly and use the approved probe leads and accessories for that tester. 12 ThinkPad i Series 1400 HMM