November 13, 2024 Joy Chan

Fanuc Robot Repair: A Comprehensive Guide

Have you ever encountered difficulties when repairing a Fanuc robot? Don't worry, this article will guide you through the process and help you feel confident in tackling any Fanuc robot repair.

Emergency Stop Procedures

While starting a robot might seem simple, knowing how to stop it immediately in an emergency is crucial. Here are three primary methods:

Power Off Stop:

This is equivalent to a Category 0 stop in IEC 60204-1.
The servo power is cut off, causing the robot to stop instantly. However, the deceleration trajectory cannot be controlled.
This method is used when an alarm occurs.

Controlled Stop:

This is equivalent to a Category 1 stop in IEC 60204-1.
The robot decelerates and stops before the servo power is cut off.
This method is used when the "SRVO-199 Control Stop" instruction is executed.

Safe Stop:

This is equivalent to a Category 2 stop in IEC 60204-1.
The robot decelerates and stops while the servo power remains on.

Note: The specific stop method used when pressing the emergency stop button or opening the safety fence depends on the robot controller's type and options, collectively known as the "stop mode."

Diagnosing Fanuc Robot Circuit Board Failures

When a robot malfunctions, follow these steps for initial diagnosis:

Observe Robot Status:Look for abnormal stops, alarm codes, or error messages.
Check Power System:Ensure the power supply, cables, fuses, and switches are functioning correctly.
Check Communication System:Verify communication between the robot and controller.
Inspect Circuit Board:Look for physical damage like burn marks, deformation, or corrosion.

Locating Faulty Components on the Circuit Board

Several methods can be used to pinpoint the exact location of a fault:

Resistance Measurement:Measure the resistance of components to detect short circuits or open circuits.
Voltage Measurement:Compare measured voltage values with normal values to identify issues in related circuits.
Waveform Analysis:Use an oscilloscope to analyze signal waveforms and detect anomalies or interference.
Component Replacement:Replace suspected faulty components to determine if the issue is resolved.

Repairing Fanuc Robot Circuit Boards

Follow these steps to repair a circuit board:

Prepare Tools and Spare Parts:Gather necessary tools and replacement components.
Remove the Circuit Board:Carefully remove the board from the robot.
Repair Faulty Components:Replace damaged components, repair broken traces, or re-solder loose pins.
Clean and Organize:Clean the board to remove dirt, oil, and solder residue.
Assemble and Test:Reinstall the repaired board and thoroughly test the robot.