Yokogawa AQ6370C optical spectrum analyzer repair

The AQ6370C is one of the most widely deployed OSAs in DWDM labs and fiber component test environments. At 600 to 1700 nm with 0.02 nm RBW and 78 dB dynamic range, it handles most optical test work without compromise. Yokogawa still supports newer models in the AQ6370 line, but the C is aging out of their coverage window. The most common AQ6370C failure we see is a failing internal hard drive. These units shipped with standard 2.5" spinning HDDs that are now 10+ years old. Slow boot times, filesystem errors, and outright boot failure are all symptomatic of HDD wear. We replace the drive with an SSD as part of this repair - it's the single best fix for a C-series unit. Sweep motor issues and monochromator drift are the next most common hardware problems. Touchscreen calibration drift and display backlight failure also show up on heavily used units. We run a full bench diagnostic with DFB references at 1310 and 1550 nm, check sweep speed and trace repeatability, and measure sensitivity and dynamic range. HDD replacement with SSD is included when the drive shows wear. Board-level repair for any electronics faults, optical path cleaning, and monochromator alignment follow. NIST-traceable calibration with cal cert completes the service.