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This support article provides a troubleshooting guide for diagnosing and repairing common failures in power supplies. The guide is based on a maintenance manual and includes step-by-step instructions to help identify the cause of the failure and perform the necessary repairs. It covers various components and circuits, as well as the tools and materials required for maintenance.

  1. Symptom Identification:
  • Observe the power supply’s appearance for any visible damage or abnormalities.
  • Check for any unusual sounds or vibrations when the power supply is operational.
  • Measure the input and output impedance with a multimeter to detect short circuits.
  1. Common Failure Analysis:
  • Lack of 390V PFC voltage: Check PFC circuit and TR1 for short circuits. Inspect components such as F2, RB1, RB2, RT1, D5, D9, D13, Q32, Q33, Q34, R311, R309, R314, R329, R330 for possible failures.
  • No output from the main or auxiliary circuits: Inspect MOS tubes, resistors, and IC chips in the respective circuits. Verify the PFC voltage and communication signals.
  • High ripple in the main output: Check and replace capacitors (C31, C32, C40, C41, C46, C47, C48, C49, C51, C52, C55, C56, C57, C59, C60, C62, C63, C64, C65, C66, C70, C71, C72, C73) if any of them are faulty.
  • Fan failure: Check for blockages or wire corrosion in the fan. Replace the fan if necessary.
  • Input circuit failure: Inspect the ON/OFF switch for any malfunctions.
  • Output cable damage: Check the 12V output cable for any physical damage or disconnection.
  1. Repair Procedures:
  • Use appropriate maintenance tools such as soldering irons, hot air guns, multimeters, pliers, and screwdrivers.
  • Follow proper electrostatic protection measures and wear an antistatic bracelet.
  • Replace defective components with identical models and specifications. Avoid using substitute materials without authorization.
  • Mark and separate repaired or replaced defective materials to prevent mixing with qualified products.
  • Record the power supply’s serial number, symptoms, causes, and repair procedures. Maintain a maintenance record for future reference.

This troubleshooting guide provides a comprehensive approach to diagnosing and repairing common power supply failures. By following the step-by-step instructions and utilizing the recommended tools, technicians can effectively identify faulty components and circuits, perform necessary repairs, and ensure the proper functioning of the power supply.