| Failure Symptom | Likely Cause | Corrective Action | |----------------|--------------|--------------------| | Status LED blinking red (2 flashes/sec) | Backplane communication timeout | Reseat the module; check for bent pins on the backplane connector. | | Analog output stuck at 0V | Blown output fuse (internal) | Replace the module; this is not field-serviceable. | | Erratic temperature readings | CJC (cold junction compensation) drift | Perform a new calibration; ensure terminal block is not near heat source. | | Module not powering on | Reverse polarity or overload | Check voltage at input terminals; remove all load and re-test. | | Intermittent network drop | IP address conflict | Assign a static IP outside DHCP range; check switch port for errors. |