Cause: Braking transistor error comes when a braking transistor error is detected. The "dba" fault specifically means the drive has detected a malfunction within the braking transistor circuit. 

dba fault in fuji FRENIC MEGA drive indicates Braking transistor error. This means a problem with the internal braking transistor. This transistor is crucial for dissipating regenerative energy generated by the motor during deceleration or when a load is overhauling.

• Visually inspect the braking resistor for any signs of damage, burning, or cracking.
• Check all wiring connections between the drive's P(+) and DB terminals and the braking resistor. Ensure they are clean and securely tightened.
• Measure the resistance of the braking resistor with a multimeter. Compare it to the specified resistance value. An open circuit (infinite resistance) or a dead short (0 ohms) indicates a faulty resistor.