120-0007

Access Service Mode

Power on the control while holding the MOD key to enter Service Mode before full system initialization

Some MOD functions require the machine manufacturer's password. Unauthorized changes may void warranty.

Check System Files

Navigate to MOD → System → File System Check and run the integrity check on the TNC: partition. Note any errors reported for files in /sys/config/ or /sys/layer/ directories

The control creates a detailed log at TNC:/sys/check.log showing exactly which files failed integrity verification

Restore Configuration Backup

Go to MOD → System → Restore and select 'Layer Configuration' or 'System Configuration' to restore from the most recent automatic backup stored in TNC:/sys/backup/

TNC controls automatically create configuration snapshots before major operations. Look for files with timestamps immediately before the problem started

Verify Layer Initialization

After restoration, perform a complete power cycle (not warm restart) and monitor the boot sequence. Access MOD → Service → System Info to verify all layers show 'Active' status

Boot to Recovery Mode

Power on while holding MOD key. If normal MOD access fails, use the emergency boot option by holding MOD + CE keys simultaneously during power-on

Emergency boot mode bypasses normal safety checks. Use only when standard MOD access fails.

Run File System Repair

In MOD menu, navigate to System → File System → Check and Repair. Select the system partition (typically labeled TNC: or SYS:) and choose 'Automatic Repair' option

For TNC 640 and newer, the repair utility can run in read-only simulation mode first—use this to assess damage without making changes

Examine Repair Log

After repair completes, review the log file at TNC:/sys/fsck.log to identify which files or directories were damaged. Pay special attention to /sys/config/ directory entries

Reinstall System Files

If repair indicates severe corruption in layer configuration areas, use MOD → System → Software Update → Repair Installation to reinstall system components without losing machine parameters

Check Update Status

Access MOD → System → Software Info and verify the version numbers for all components. Look for mismatched versions between 'NC Software', 'PLC Software', and 'System Base' entries

All three version components should have matching build dates. A date mismatch indicates an incomplete update cycle

Review Update Log

Examine the file TNC:/sys/update.log for error messages or incomplete installation steps. Look specifically for 'Layer configuration failed' or 'Configuration rollback' messages

Complete or Rollback Update

In MOD → System → Software Update, choose either 'Complete Interrupted Update' if the new version is desired, or 'Rollback to Previous Version' to restore the last known-good configuration

Rollback will revert all software components and may lose recent parameter changes. Create a backup via MOD → Backup before proceeding.

Perform Clean Update

If completion/rollback fails, perform a fresh installation from original Heidenhain media using MOD → System → Software Update → Clean Install, then restore machine parameters from backup

Check Hardware Configuration

Access MOD → System → Hardware Configuration and compare the displayed hardware against the physical installation. Note any components showing 'Not Found' or 'Configuration Error' status