Apply power. The manual’s Table 4-2 lists BI light sequences. A steady “S-TEC” light means success. Flashing indicates a specific failure (e.g., rate gyro disconnected or servo stalled).
Start with the rate gyro. Use a digital protractor to verify alignment. Then mount the computer and servos. Torque servo mounting bolts to the manual’s specification (e.g., 25 in-lbs for roll servo clamps). S-tec 55x Installation Manual
Connect power and ground first. Then connect the gyro, servos, and annunciator. Leave NAV/GPS connections for last. Apply power
With power off, measure resistance between each servo motor lead and ground. The manual specifies >1 MOhm. Any lower indicates a short. S-tec 55x Installation Manual