Fault Causes: Depleted or aged battery (unable to charge); damaged power adapter (abnormal output voltage); failure of internal power management circuit (e.g., burned power chip, blown fuse); automatic shutdown protection triggered by instrument overheating (blocked heat dissipation holes, damaged cooling fan).
Maintenance Methods: Connect the original power adapter for charging; replace the battery with the same model if it cannot charge for a long time; test the output voltage of the power adapter with a multimeter and replace the adapter if it does not meet the rated value (usually 15V/3A); disassemble the instrument to inspect the power management circuit and replace the burned power chip or blown fuse; clean dust from heat dissipation holes, check if the cooling fan rotates, and replace the fan if damaged.
Fault Causes: Contaminated (dust or oil blockage) or physically damaged (bent pins) optical test interface; degraded or damaged internal optical detector (e.g., PIN diode); loss of optical power calibration data (memory chip failure); incorrect test mode settings (e.g., wavelength selection mismatched with the actual light source).
Maintenance Methods: Clean the optical test interface with a dust-free cotton swab dipped in absolute ethanol, repair bent pins, and replace the interface assembly if severely damaged; test the responsivity of the optical detector and replace the detector if degraded or damaged; rewrite or restore optical power calibration data via official calibration software; verify the test mode to ensure parameters such as wavelength and range match the actual test light source.
Fault Causes: Insufficient input optical signal strength (below the instrument's receiving sensitivity); damaged or loosely connected test cable (e.g., optical patch cord); incorrect BERT parameter settings (e.g., code pattern, rate mismatched with the tested signal); failure of internal signal processing module (e.g., clock recovery chip).
Maintenance Methods: Use an optical power meter to confirm the input optical signal strength; adjust the light source power or shorten the transmission distance if the strength is insufficient; replace with a spare optical patch cord and re-plug to ensure a secure connection; enter the test menu to verify and correct parameters such as code pattern (e.g., PRBS31) and rate; inspect the internal signal processing module and replace the faulty clock recovery chip or signal conditioning components.
