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Heidenhain Controller
System · Intermediate · 30-120 minutes
HEIDENHAIN 120-0016 -
This alarm indicates a breakdown in the TNC control's front-end dialog management system, which handles all operator interface interactions. The root cause is typically corrupted system software files, exhausted system resources, or hardware failures affecting the MC board's ability to process user interface operations. Since this is an internal software fault that the control cannot self-recover from, it requires systematic diagnosis starting with software integrity checks before investigating hardware issues.
120-0016
HEIDENHAIN 120-0016 -
This TNC7/TNC 640 error (120-0016) relates to ''. Internal software error with front end/dialogs.
Root Cause Summary
This alarm indicates a breakdown in the TNC control's front-end dialog management system, which handles all operator interface interactions. The root cause is typically corrupted system software files, exhausted system resources, or hardware failures affecting the MC board's ability to process user interface operations. Since this is an internal software fault that the control cannot self-recover from, it requires systematic diagnosis starting with software integrity checks before investigating hardware issues.
Safety
- Refer to Heidenhain service manual
- Ensure qualified technician performs repairs
Causes and Fixes
- 1
Document Current State
Note exactly which operation was being performed when alarm occurred (opening a cycle dialog, entering MDI, changing operating mode, etc.). Record control software version from MOD > About.
Take photos of the alarm screen including any error codes or messages displayed before clearing.
- 2
Check Protocol Files
Navigate to MOD > File Management > TNC:\system\protocol. Review the most recent .log files for entries containing 'Dialog', 'Frontend', or 'Exception'. Copy these files to external media for service analysis.
The file 'error.log' and files with current date stamps are most relevant for diagnosis.
- 3
Boot into Service Mode
Power down control completely. Hold MOD key and power up to enter Service Mode. Select 'System Diagnostics' and run the 'Check File System' function to verify system file integrity.
Service Mode functions can affect control operation. Document any changes made.
- 4
Restore System Software
In Service Mode, select 'Restore System' and choose a verified backup from external media or the recovery partition. Follow the restore wizard completely, allowing full system reinitialization.
Ensure machine parameters and PLC program are backed up before restore as some configurations may revert.
- 5
Verify After Restore
After restoration and reboot, systematically test all dialog operations: cycle input, tool table editing, preset table, and parameter entry to confirm front-end stability.
Run the control through typical operator workflows before returning to production.
Call a technician if:
- ·Software update required beyond operator capability
- ·Network infrastructure changes needed
- ·Persistent alarm after all troubleshooting steps
Prevention
- Regularly update TNC software
- Monitor network drive connectivity
- Maintain stable network infrastructure
- Document network configuration changes
Common Mistakes
- Ignoring Windows CE event logs
- Not testing network connectivity before configuration
- Mixing different SMB protocol versions
- Forgetting to restart network services after changes
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Always verify with your machine manual or a certified technician before performing service procedures.