Guidelines for trained service techniciansThis section contains information for trained service technicians.Inspecting for unsafe conditionsUse the information in this section to help you identify potential unsafe conditions inan IBM product that you are working on. Each IBM product, as it was designed andmanufactured, has required safety items to protect users and service techniciansfrom injury. The information in this section addresses only those items. Use goodjudgment to identify potential unsafe conditions that might be caused by non-IBMalterations or attachment of non-IBM features or options that are not addressed inthis section. If you identify an unsafe condition, you must determine how serious thehazard is and whether you must correct the problem before you work on theproduct.Consider the following conditions and the safety hazards that they present:v Electrical hazards, especially primary power. Primary voltage on the frame cancause serious or fatal electrical shock.v Explosive hazards, such as a damaged CRT face or a bulging capacitor.v Mechanical hazards, such as loose or missing hardware.To inspect the product for potential unsafe conditions, complete the following steps:1. Make sure that the power is off and the power cord is disconnected.2. Make sure that the exterior cover is not damaged, loose, or broken, andobserve any sharp edges.3. Check the power cord:v Make sure that the third-wire ground connector is in good condition. Use ameter to measure third-wire ground continuity for 0.1 ohm or less betweenthe external ground pin and the frame ground.v Make sure that the power cord is the correct type, as specified in “Powercords” on page 37.v Make sure that the insulation is not frayed or worn.4. Remove the cover.5. Check for any obvious non-IBM alterations. Use good judgment as to the safetyof any non-IBM alterations.6. Check inside the server for any obvious unsafe conditions, such as metal filings,contamination, water or other liquid, or signs of fire or smoke damage.7. Check for worn, frayed, or pinched cables.8. Make sure that the power-supply cover fasteners (screws or rivets) have notbeen removed or tampered with.Guidelines for servicing electrical equipmentObserve the following guidelines when servicing electrical equipment:v Check the area for electrical hazards such as moist floors, nongrounded powerextension cords, power surges, and missing safety grounds.v Use only approved tools and test equipment. Some hand tools have handles thatare covered with a soft material that does not provide insulation from liveelectrical currents.v Regularly inspect and maintain your electrical hand tools for safe operationalcondition. Do not use worn or broken tools or testers.viii IBM System x3550 Type 7978 and 1913: Problem Determination and Service Guide
