Inspecting for unsafe conditions

Use this information to help you identify potential unsafe conditions in a device that you are working on.

Each device, as it was designed and manufactured, has required safety items to protect users and service technicians from injury. The information in this section addresses only those items. Use good judgment to identify potential unsafe conditions that might be caused by unsupported alterations or attachment of unsupported features or optional devices that are not addressed in this section. If you identify an unsafe condition, you must determine how serious the hazard is and whether you must correct the problem before you work on the product.

Consider the following conditions and the safety hazards that they present:

To inspect the product for potential unsafe conditions, complete the following steps:

  1. Make sure that the power is off and the power cords are disconnected.
  2. Make sure that the exterior cover is not damaged, loose, or broken, and observe any sharp edges.
  3. Check the power cords:
    • Make sure that the third-wire ground connector is in good condition. Use a meter to measure third-wire ground continuity for 0.1 ohm or less between the external ground pin and the frame ground.
    • Make sure that the power cords are the correct type.
    • Make sure that the insulation is not frayed or worn.
  4. Remove the cover.
  5. Check for any obvious unsupported alterations. Use good judgment as to the safety of any unsupported alterations.
  6. Check inside the system 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 not been removed or tampered with.