The Bycan RB‑14/28‑25 is a dual‑mode aircraft ramp power supply and battery charger that delivers filtered 14 V or 28 V DC at up to 25 A while protecting the output with an internal circuit breaker. Common failure modes include overheating of the thermal management fins, tripping of the built‑in breaker due to shorted loads or overcurrent, degradation of the power‑line filtering capacitors leading to voltage ripple, and failure of the AC input rectifier causing unstable DC output. First‑check diagnostics should verify that the unit is receiving correct 220 V/50 Hz AC, inspect the internal fuse and breaker for signs of tripping or damage, and measure the output voltage under no load to confirm proper regulation before proceeding with component replacement.[oss-gpt-20b]