The Bycan PS‑2850A is a dual‑purpose aircraft ramp power supply and battery charger that delivers a filtered 28 V DC output at up to 50 A for test and recharge functions. Common failure points on this model include blown main fuses, degraded electrolytic capacitors in the rectifier/filter stage, overheating of the internal transformer or power MOSFETs, and loss of output voltage due to worn regulator circuitry. First‑check diagnostics should verify that the 230 V AC input is present and within spec, inspect all fuses and the main filter capacitor for signs of damage, and measure the 28 V DC rail under load to confirm correct regulation before proceeding with component replacement or board rework.[oss-gpt-20b]