FANUC Alarm SRVO-222 — SERVO Lack of Amp (Amp:…)
Error- Hardware
- FSSB link and axis control card
- Controllers
- R-J3iB / R-30iA
- FANUC class
- SERVO
Manufacturer wording — SERVO Lack of Amp (Amp:%d)
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC SRVO-222 (“SERVO Lack of Amp (Amp:…)”): The FSSB optical cable is not connected to an SVM amplifier. First check: 1. Verify that the optical cable is securely connected to the SVM amplifier.
Updated 2026-10-22 · LogrobotLM reference
Description
The FSSB optical cable is not connected to an SVM amplifier.
Remedy
1. Verify that the optical cable is securely connected to the SVM amplifier. 2. Replace the optical cable. 3. Check whether power is properly supplied to the SVM. 4. Verify that no problems exist with each SVM input voltage. 5. Replace the SVM.
Field diagnosis
No amplifier responded to the power-up sequence.
What to check
- Amplifier LEDs off: check the power supply and all connectors between the emergency stop unit and the amplifier.
- Then, with the power off, disconnect the encoder cables (JF1/JF2) and switch the power back on: if the code disappears, an encoder or its cable is short-circuited.
- Note: Often the real cause of an accompanying SRVO-038.
Related codes
Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →