Assessments - 4, GPA: 4.3
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Be sure that all built-in protective devices are replaced. Restore any missing protective shields. 2. When reinstalling the chassis and its assemblies, be sure to restore all protective devices, including nonmetallic control knobs and compartment covers. 3. Make sure there are no cabinet openings through which people - particularly children - might insert fingers and contact dangerous voltages. Such openings include excessively wide cabinet ventilation slots and improperly fitted covers and drawers. 4. Design Alteration Warning: Never alter or add to the mechanical or electrical design of the SECR. Unauthorized alterations might create a safety hazard. Also, any design changes or additions will void the manufacturer’s warranty. 5. Components, parts and wiring that appear to have overheated or that are otherwise damaged should be replaced with parts that meet the original specifications. Always determine the cause of damage or over-heating, and correct any potential hazards. CAUTION There is the danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Dispose used batteries according to the manufacturer’s instructions. 6. Observe the original lead dress, especially near the following areas: sharp edges, and especially the AC and high voltage supplies. Always inspect for pinched, out-of-place, or frayed wiring. Do not change the spacing between components and the printed circuit board. Check the AC power cord for damage. Make sure that leads and components do not touch thermally hot parts. 7. Product Safety Notice: Some electrical and mechanical parts have special safety-related characteristics that might not be obvious from visual inspection. These safety features and the protection they give might be lost if the replacement component differs from the original - even if the replacement is rated for higher voltage, wattage, etc. Components that are critical for safety are indicated in the circuit diagram by shading, ( ) or ( ). Use replacement components that have the same ratings, especially for flame resistance and dielectric strength specifications. A replacement part that does not have the same safety characteristics as the original might create shock, fire or other hazards. ATTENTION ll y a danger d’explosion s’il y a remplacement incorrect de la batterie. Remplacer uniquement avec une batterie du meme type ou d’un type equivalent recommande par le constructeur. Mettre au rebut les batteries usagees conformement aux instructions du fabricant. SAFETY NOTICE: "For pluggable equipment, the socket-outlet shall be installed near the equipment and shall be easily accessible." 1-2 Servicing Precautions WARNING: First read the-Safety Precautions-section of this manual. If some unforeseen circumstance creates a conflict between the servicing and safety precautions, always follow the safety precautions. WARNING: An electrolytic capacitor installed with the wrong polarity might explode. 1. Servicing precautions are printed on the cabinet. Follow them. 2. Always unplug the units AC power cord from the AC power source before attempting to: (a) Remove or reinstall any component or assembly (b) Disconnect an electrical plug or connector (c) Connect a test component in parallel with an electrolytic capacitor 3. Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used. The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such elements to their original position. 4. After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the portion around the serviced part has not been damaged. 5. Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels and input terminals). 6. Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON. Connect an insulation resistance meter (500V) to the blades of AC plug. The insulation resistance between each blade of the AC plug and accessible conductive parts (see above) should be greater than 1 megohm. 7. Never defeat any of the B+ voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed. 8. Always connect an instrument’s ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrument’s ground lead last. 1-3 Precautions for Electrostatic Sensitive Devices (ESDs) 1. Some semiconductor (solid state) devices are easily damaged by static electricity. Such components are called Electrostatic Sensitive Devices (ESDs); examples include integrated circuits and some field- effect transistors. The following techniques will reduce the occurrence of component damage caused by static electricity. 2. Immediately before handling any semiconduc...