The Red Baron RB‑14/28‑25 is an aircraft ramp power unit that supplies selectable 14 V or 28 V DC at up to 25 A for avionics and actuator testing. Common failure modes include capacitor degradation (especially the output filtering caps), overheating of the internal regulator, blown main fuses, and loss of the selector switch contact integrity. Initial checks should verify input AC voltage and frequency, confirm that the unit’s indicator LEDs or status LEDs are functioning, and measure the DC output under no‑load conditions to ensure correct 14 V/28 V selection. If the output is low or erratic, inspect the regulator ICs, fuse condition, and capacitor ESR values before proceeding with component replacement.[oss-gpt-20b]