The Bycan BA‑14/28‑50P is a dual‑voltage aircraft ramp power supply and battery charger that delivers filtered 14 V or 28 V DC at up to 50 A for avionics testing and battery recharging. Common failure modes include degraded electrolytic capacitors on the output filter, blown main fuses, and voltage regulator drift causing over‑ or under‑voltage conditions; overheating of the internal heat sink can also trigger protection shutdowns. First‑check diagnostics: verify input power integrity (APU 115 V AC), measure output voltages with a calibrated multimeter while toggling between 14 V and 28 V modes, inspect fuses and capacitor banks for bulging or leakage, and review any fault codes displayed on the unit’s indicator panel.[oss-gpt-20b]