Ando AQ6317B optical spectrum analyzer repair

The AQ6317B sits at the top of Ando's legacy OSA lineup - 600 to 1750 nm, 0.02 nm RBW, wide dynamic range. Ando no longer exists as a support organization; Yokogawa acquired the product line but not the obligation to repair older hardware. When an AQ6317B fails today, the OEM route is a dead end. Most failures we see on the AQ6317B fall into a handful of categories. Grating motor sluggishness or stall is the most common - the sweep just stops, or the unit takes minutes to complete a span it used to do in seconds. CRT display issues come second: horizontal brightness loss, flickering, or complete display failure. Wavelength drift past the ±0.02 nm spec shows up as consistently wrong peak readings and usually traces back to a sweep encoder or monochromator alignment issue. Boot hangs that clear on power cycle are almost always a capacitor on the sweep control board, not firmware. We start with a full bench diagnostic using DFB reference sources at 1310 nm and 1550 nm plus a broadband source across span. Repair is component-level - we replace failed caps, ICs, and sweep drivers on the board, not the whole board. Optical path gets cleaned and realigned. Grating and monochromator are adjusted using a precision reference. Final calibration uses NIST-traceable lasers; you get the unit back with a cal cert showing before-and-after data.