Replace the main detector

Hazard: Physical shock or excessive force applied to the detector/DAS during removal or remounting

Consequence: Damage to the main detector array (sensitive detector electronics)

Avoidance: Handle the assembly gently at all times; never shock or force it while removing or remounting

Hazard: ESD or contamination exposure while the DAS PWB is extracted and transferred between the old and new main detector

Consequence: Damage to the DAS PWB

Avoidance: Wear new clean gloves; use an antistatic mat and antistatic wristband during the transfer; confirm the PWB is properly/securely inserted (viewed from the oblique direction) before continuing

Hazard: Detector/DAS assembly striking the patient couch during insertion — interference can easily occur in the tight clearance between couch and gantry

Consequence: Damage to the DAS or to the couch top surface

Avoidance: Insert the detector/DAS from the oblique direction carefully; place a blanket on the couch top to protect it

Hazard: Main detector not reaching or holding its regulated internal temperature after replacement (heater rated 500 W / 200 VAC, thermal fuse rated 72°C, regulated to 37±1°C)

Consequence: Artifacts in acquired images

Avoidance: Confirm the temperature controller's current-temperature display rises gradually and stabilizes between 36.0–38.0°C with the OT1 (red) lamp blinking, before returning the system to clinical use

Hazard: Starting calibration data acquisition before the replaced detector has thermally stabilized

Consequence: Invalid/unusable calibration data, forcing recalibration

Avoidance: Wait at least 3 hours after system power-ON before starting calibration acquisition (2–3 hours are needed for detector temperature stabilization; may vary with room temperature)