Service Home Servo Bar 300 - Troubleshooting Guide - TG0126
Last updated: 10/15/2025

Servo Bar 300 - Troubleshooting Guide

TG0126

Introduction

Servo Bar 300

  1. Home switch
  2. EOB (End of Bar) switch
  3. Load bar switch
  4. Load "Q" switch
  5. Ballscrew (trolley)
  6. Servo motor (trolley)
  7. DC motor (bar feeder)
  8. Charging tray
  9. Transfer tray

Symptom Table

Symptom Possible Cause Corrective Action
Alarm 702 V AXIS POSITION ERROR The trolley hit an obstruction. Adjust the charging tray.
A bar is stuck. Clear bar path.
Alarm 712 V AXIS SERVO OVERLOAD The V Axis ballscrew is not lubricated. Check for ballscrew damage.
The servo motor does not operate correctly. Troubleshoot the servo motor.
Alarm 452 SERVO BAR MOTOR TIMEOUT The bar feeder lifter hit an obstruction. Remove obstructions from the lifter.
The DC motor brushes are worn. Measure resistance of the DC motor.
The proximity sensor does not operate correctly. (Load bar) Measure voltage to the proximity sensor.
There is no voltage to the DC motor. Measure voltage to the DC motor.
Alarm 423 SERVO BAR EOB SWITCH POSITION The proximity sensor does not operate correctly. (EOB switch) Measure voltage to the proximity sensor.
Alarm 175 GROUND FAULT DETECTED Cables are damaged or there is a contaminated electrical connection. Check for connector damage.
The brushes are contaminated or there is a carbon buildup. Check for contamination and remove dust.
Alarm 1015 CHECK SENSOR OR BAR The proximity sensor does not operate correctly (Load "Q"). Measure voltage to the proximity sensor.
Noisy The V Axis ballscrew is not lubricated. Check for ballscrew damage.
Inconsistent push lengths. Affected by previous push, pushrod timing delay, spindle liner size, chuck jaw size or grip strength. Troubleshoot the pusher.
Pusher positions incorrectly. Incorrecet parameters for V-Axis ballscrew pitch. See the Barfeeder - Servo Bar 300 - 10mm - Ballscrew - Parameters - CHC procedure for setting the parameters for the installed ballscrew pitch.

Barfeeder Trolley

Corrective Action:

Make sure bar feeder charging tray is not too high. When the tray is too high, the bar feeder can attempt to load two bars. Refer to the bar feeder manual for more information.

Press [RESET] to clear the alarm.

Handle jog the V Axis away from the obstruction.

The Bar is Stuck

Corrective Action:

  1. Squared-corner bar
  2. Transfer tray
  3. Chamfered-corner bar

The bar can get stuck when:

  • The bar is not chamfered: Bars must have a smooth path. Any sharp corner in the bar path must be removed. Sharp corners can cause problems when you load a bar. Collets and chucks must have lead-in corners chamfered. Leading ends of a bar must be chamfered. When you create liners or small use bar discs, use a generous lead-in chamfer.
  • The bar feeder is not aligned correctly: Refer to the bar feeder manual; it has specific instructions on how to correctly position the bar feeder and adjust the transfer tray.
  • The bar is caught on the chuck jaw: When you load a new bar, add a M19 code to your program to orient the chuck, and give the bar clearance to pass the chuck jaws.

Press [RESET] to clear the alarm.

Handle jog the V Axis away from the obstruction.

Servo Motor

Corrective Action:

Make sure the motor connections are properly seated and the cables are not damaged.

Go to Servo Amplifier - Troubleshooting Guide and Sigma 5 - Axis Servo Motor and Cables - Troubleshooting Guide. Check for shorts to the motor.

Bar Feeder Lifter

Corrective Action:

Refer to: Haas Bar Feeder - Troubleshooting Guide

Motor Brushes

Corrective Action:

Refer to: Haas Bar Feeder - Troubleshooting Guide

Proximity Sensors

Corrective Action:

Find the correct sensor to troubleshoot:

  1. Load bar (Alarm 452)
  2. Home switch (Alarm 469)
  3. EOB switch (Alarm 423)
  4. Load "Q" (Alarm 1015)

Test the sensor for correct operation: hold a key or other steel object in front of the sensor. If the sensor lights up, the sensor is not faulty. If the sensor does not light up, continue to further troubleshoot the proximity sensor.

Disconnect the cable [1] from the sensor. Use the marker [2] on the cable connector to measure the correct pins. Measure the voltage between the pins [3] and [4] on the cable connector. Make sure to use a multimeter with needle tipped probes.

The correct voltage is 12 VDC.

If voltage is correct, the sensor is at fault. Go to Proximity Sensor - Troubleshooting Guide to further troubleshoot the proximity sensor.

If there is no voltage, go to I/O PCB - Troubleshooting Guide (Classic Haas Control).

DC Motor Voltage Inspection

Corrective Action:

Refer to: Haas Bar Feeder - Troubleshooting Guide

Electrical Cables

Corrective Action:

Perform a visual inspection of the motor cable and connectors. Make sure that the cable is in good condition and that the connectors are clean and secure.

Inconsistent Push Lengths

Corrective Action:

Refer to: Haas Bar Feeder - Troubleshooting Guide

Electrical Diagram