PLCS7-1200Verified · sol.ls-electric.com
S7-1200 LED-ERROR-ON — ERROR LED on
Critical — power cycle required
CAUSE
Why does it occur?
Fatal system error — possible CPU firmware/hardware fault or memory card problem.
REMEDY · Step by step
How to fix it?
Power-cycle once, boot with the memory card removed; if it recurs, reinstall firmware or replace the unit.
Do not reset repeatedly before identifying the cause. Repeated resets while ignoring a trip/alarm can cause secondary damage (IGBT failure, motor winding damage, etc.).
SOURCE
Related manual page
Summary based on the official Siemens AG manual. For accurate and complete information, always consult the official manual.
Open official manual ↗CALLBACK
Request an expert callback
A 12-year automation/SI engineer responds directly. Reply within 1–3 business days.