PS0002

Press SYSTEM > PARAM and check parameter 0000 bit 0 (TVP). If TVP=1, TV check is enabled. Record current setting.

Press EDIT mode, retrieve the program number shown in alarm history (SYSTEM > ALARM > HISTORY). Check for garbled characters, incomplete blocks, or special characters in the flagged block.

Delete corrupted program and retransfer from verified backup source using proper RS-232C settings (baud rate, parity, stop bits matching CNC parameter 0020, 0021, 0022).

If alarm persists and TV check is not required for your application, set parameter 0000#0=0 to disable TV check after verifying with machine tool builder documentation.

Disabling TV check removes a data integrity safeguard. Ensure reliable program transfer methods are in place.

Press SYSTEM > PARAM and verify RS-232C parameters: 0020 (I/O channel), 0021 (baud rate), 0022 (stop bits/parity). Ensure they match external device settings exactly.

Inspect RS-232C cable for damage, proper shielding, and secure DB-9/DB-25 connector attachment. Replace with shielded cable if suspect. Route away from servo amplifier cables and power lines.

Test program transfer using drip-feed (tape mode) with reduced baud rate (2400 or 4800 bps) set in parameter 0021. Monitor for alarm recurrence.

Check ground continuity between CNC cabinet and PC/DNC device. Verify proper earth grounding on both devices to eliminate ground loop noise.

Use isolated ground, not daisy-chained ground connections.

Press SYSTEM > DIAGNOSIS and check diagnostic 0300 (Battery voltage). If voltage <2.7V on applicable systems, battery requires replacement. Check diagnostic 0007 for memory error flags.

Low battery can cause immediate data loss. Replace battery under power (hot swap) or backup all data first.

Execute full program backup via RS-232C or memory card. Clear all programs (press EDIT > PROG > O-9999 > DELETE ALL after backup), then restore from known-good backup source.

If alarm persists after restore, suspect Flash ROM or SRAM hardware failure. Contact Fanuc service to test/replace CNC main board or memory module.

Check ambient temperature around CNC control. Excessive heat (>45°C) can cause memory instability. Verify cooling fans operational and air filters clean.