Heidenhain codes
HeidenhainPower SupplyIntermediate30-120 minutes

231-8040

HEIDENHAIN 231-8040 - 8040 Heat sink temp. in UV 1xx

8040 Heat sink temp. in UV 1xx

This TNC 640 error indicates an internal control fault. The issue relates to Heat-sink temperature of UV 1xx power supply unit too high.

Root Cause Summary

HEIDENHAIN alarm 231-8040 indicates excessive heat-sink temperature in the UV 1xx power supply unit, typically caused by inadequate cooling or thermal management issues. The TNC control monitors internal temperatures and triggers this alarm when thermal thresholds are exceeded to prevent component damage.

Safety

  • Refer to Heidenhain service manual
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Access electrical cabinet

    Power down the TNC system completely and open the electrical cabinet to access the UV 1xx power supply unit.

    Ensure complete power isolation before opening electrical cabinet

  2. 2

    Inspect filter pads

    Locate filter pads on the UV power supply unit intake and exhaust areas. Check for dust accumulation, oil contamination, or physical blockage.

    Use compressed air at low pressure (max 2 bar) to avoid damaging filter material

  3. 3

    Clean or replace filters

    Remove filter pads and clean with compressed air or replace if heavily contaminated. Ensure proper reinstallation with correct orientation.

    Keep spare filter pads in stock - part numbers are typically found on the UV unit label

  4. 4

    Verify airflow restoration

    Power up system and monitor temperature readings through TNC diagnostic menus to confirm improved cooling performance.

DIY Feasiblehigh confidence

Call a technician if:

  • ·UV power supply internal component failure suspected
  • ·Multiple related alarms persist after basic troubleshooting
  • ·Temperature sensor replacement required

Prevention

  • Replace filter pads every 6 months in normal environments
  • Monitor electrical cabinet ambient temperature regularly
  • Perform annual cooling system maintenance
  • Keep spare cooling fans in inventory

Common Mistakes

  • Ignoring gradual temperature increases before alarm triggers
  • Using incorrect filter pad specifications
  • Failing to verify proper fan airflow direction during replacement
  • Not addressing root cause of elevated cabinet temperature

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Always verify with your machine manual or a certified technician before performing service procedures.