Cybex Q25CI is a treadmill power supply module that interfaces with the Cybex Trotter AD‑11803 controller and related console boards (e.g., 044‑01, 400 T). Common failure points for this class of industrial power supplies include degraded rectifier diodes, failing voltage regulators, or burnt capacitors under high load; motor driver ICs can also short out if the treadmill runs at peak speed. Begin troubleshooting by verifying that the incoming mains (115 VAC ±5% 60 Hz) is present and within spec, then check the output rail voltages against the datasheet for the Q25CI board. Inspect for visual signs of damage such as burn marks or swollen electrolytics, and review any error codes displayed on the treadmill console that may point to a power‑supply fault.[oss-gpt-20b]