Lenovo ThinkCentre M55 User Manual - Page 11

shorten the life of the battery and can also pose a safety hazard. Do not let rechargeable Lithium-Ion batteries completely discharge or store these batteries in a discharged state. Heat and product ventilation Computers generate heat when turned on and when batteries are charging. Notebook computers can generate a significant amount of heat due to their compact size. Always follow these basic precautions: v Do not leave the base of your notebook computer in contact with your lap or any part of your body for an extended period when the computer is functioning or when the battery is charging. Your computer produces some heat during normal operation. Extended contact with the body could cause discomfort or, potentially, a skin burn. v Do not operate your computer or charge the battery near flammable materials or in explosive environments. v Ventilation slots, fans and/or heat sinks are provided with the product for safety, comfort, and reliable operation. These features might inadvertently become blocked by placing the product on a bed, sofa, carpet, or other flexible surface. Never block, cover or disable these features. You should inspect your desktop computer for dust accumulation at least once every three months. Before inspecting your computer, turn off the power and unplug the computer's power cord from the electrical outlet; then remove any dust from vents and perforations in the bezel. If you notice external dust accumulation, you should also examine and remove dust from the inside of the computer including heat sink inlet fins, power supply vents, and fans. Always turn off and unplug the computer before opening the cover. If possible, avoid operating your computer within 2 feet of high-traffic areas. If you must operate your computer in or near a high-traffic area, you should inspect and, if necessary, clean your computer more frequently. For your safety and to maintain optimum computer performance, always follow these basic precautions with your desktop computer: v Keep the cover closed whenever the computer is plugged in. v Regularly inspect the outside of the computer for dust accumulation. v Remove dust from vents and any perforations in the bezel. More frequent cleanings might be required for computers in dusty or high-traffic areas. v Do not restrict or block any ventilation openings. v Do not store or operate your computer inside furniture, as this might increase the risk of overheating. v Airflow temperatures into the computer should not exceed 35° C (95° F). v Do not use non-desktop air filtration devices. CD and DVD drive safety CD and DVD drives spin discs at a high speed. If a CD or DVD is cracked or otherwise physically damaged, it is possible for the disc to break apart or even shatter when the CD and DVD drives are in use. To protect against possible injury due to this situation, and to reduce the risk of damage to your machine, do the following: v Always store CD and DVD discs in their original packaging. v Always store CD and DVD discs out of direct sunlight and away from direct heat sources. Important safety information ix