JUKI FX-3R Y Servo Amplifier MR-J3-200BN-KM084U646 40104696

The JUKI 40104696 MR-J3-200BN-KM084U646 Y Servo Amplifier is a 2kW servo drive designed for the Y-axis motion system of JUKI FX-3R and FX-3RA SMT placement machines. The complete model identification, including the KM084U646 suffix, is important when selecting a replacement because similar MR-J3 servo amplifiers may use different machine-specific configurations or axis applications. Industry parts references identify 40104696 specifically as the FX-3R/FX-3RA Y-axis 2kW amplifier.

The unit is based on Mitsubishi Electric's MELSERVO-J3 MR-J3-200BN platform. The standard MR-J3-200BN is rated at 2kW, uses SSCNET III communication, belongs to the 200V class, and is designed for high-performance servo control.

For SMT factories maintaining JUKI FX-series machines, this amplifier is an important spare part for troubleshooting Y-axis servo alarms, motion failures, unstable positioning, or amplifier-related machine downtime.

Cause

Servo amplifiers operate continuously during SMT production, repeatedly controlling servo motor speed, torque, acceleration, deceleration, and positioning. Long operating hours combined with electrical and environmental conditions can eventually lead to servo-system problems.

Common causes that may require inspection or replacement include:

• Long-term heat exposure inside the electrical cabinet.
• Poor ventilation or blocked cooling airflow.
• Abnormal input voltage or unstable power conditions.
• Aging internal electronic components.
• Loose motor, encoder, or communication connections.
• Damaged servo motor cables.
• Excessive mechanical resistance on the Y-axis.
• Communication problems between the motion controller and amplifier.
• Incorrect grounding or electrical noise.
• Previous repairs using an incompatible amplifier version.

A servo alarm does not automatically mean that the amplifier itself is defective. The motor, cables, controller, communication network, and mechanical axis should also be inspected before replacing the unit.

Solution

When troubleshooting confirms an amplifier-related failure, the correct replacement should match the original machine configuration as closely as possible.

For this application, verify the following identification:

Using the full part number and complete amplifier suffix helps reduce the risk of ordering an incorrect X-axis version or another visually similar MR-J3 servo drive.

Before installation, technicians should also inspect the Y-axis motor, motor cable, feedback connections, communication cable, grounding, power supply, and mechanical movement. Correcting external problems before installing the replacement amplifier can help prevent repeated alarms.

Specifications

Product Specifications

The standard Mitsubishi MR-J3-200BN platform is specified as a 2kW SSCNET III servo amplifier with three-phase AC 200–230V main-circuit input, three-phase AC 170V servo output, 11A rated output current, and sine-wave PWM/current control. These are base-model specifications; the machine-specific KM084U646 version should always be verified against the original nameplate before replacement.

Base MR-J3-200BN Technical Reference

Related Servo Amplifier Comparison

Parts references distinguish 40104696 / KM084U646 as the Y-axis version and 40104695 / KM084U645 as the X-axis version for FX-3R/FX-3RA equipment. Similar appearance or identical power rating should therefore not be used as the only selection criterion.

Important: These models should not be treated as automatically interchangeable. Always verify the machine model, axis, JUKI part number, complete servo model, connector configuration, and original amplifier label.

Application

The JUKI 40104696 servo amplifier is mainly used in the Y-axis motion-control system of compatible JUKI SMT placement equipment.

Typical Applications

During normal production, the placement machine repeatedly performs high-speed motion and positioning cycles. The servo amplifier supplies controlled electrical power to the corresponding servo motor according to commands from the machine control system.

This makes the amplifier particularly important in factories manufacturing automotive electronics, consumer electronics, industrial control boards, communication equipment, LED products, power electronics, and other PCB assemblies.

How It Works

The servo amplifier functions between the machine motion controller and the servo motor.

First, the machine controller calculates the required Y-axis movement according to the placement program. Position, speed, acceleration, and timing commands are then transmitted through the servo-control network.

The MR-J3-B platform supports SSCNET III optical communication, which Mitsubishi designed for high-speed synchronized servo communication and improved resistance to electrical noise.

After receiving the motion command, the amplifier controls the electrical output delivered to the servo motor. The motor then drives the mechanical Y-axis system.

Encoder feedback allows the control system to compare the commanded movement with actual motor movement. The servo system continuously corrects the difference, helping the machine achieve repeatable positioning during component placement.

The general control sequence is:

Motion Controller → Servo Communication → Servo Amplifier → Servo Motor → Mechanical Y Axis → Encoder Feedback

If the amplifier cannot correctly process commands or regulate motor power, the machine may generate servo alarms, fail to enable the axis, or stop Y-axis movement.

How To Choose

1. Match the JUKI Part Number

The preferred identification for this product is:

40104696

Do not order only by appearance.

2. Check the Complete Model

Confirm the full marking:

MR-J3-200BN-KM084U646

The suffix is important because customized MR-J3 versions may have different applications.

3. Confirm the Machine

This product is identified for:

JUKI FX-3R / FX-3RA.

4. Confirm the Axis

This version is used for the Y axis.

Do not confuse it with 40104695 MR-J3-200BN-KM084U645, which is identified for the X-axis application.

5. Confirm the Power Rating

The required capacity is:

2kW

The standard MR-J3-200BN base amplifier is also specified by Mitsubishi as a 2kW model.

6. Compare the Original Nameplate

Before ordering, provide a clear photo of the existing amplifier showing:

• Complete model number.
• JUKI part number.
• Machine model.
• Power rating.
• Connector area.
• Existing label information.

7. Check the Complete Servo System

If the machine has repeated servo alarms, inspect the motor, cables, connectors, communication system, cooling condition, power supply, and mechanical axis before replacing the amplifier.

FAQ

Q1: What machine is JUKI 40104696 used for?

The 40104696 MR-J3-200BN-KM084U646 is identified as a 2kW Y-axis servo amplifier for JUKI FX-3R and FX-3RA SMT placement machines. Always confirm the original amplifier label before ordering.

Q2: Is MR-J3-200BN-KM084U646 a 2kW servo amplifier?

Yes. The application-specific unit is listed as 2kW, while Mitsubishi officially specifies the standard MR-J3-200BN base platform as a 2kW, 200V-class SSCNET III servo amplifier.

Q3: Can MR-J3-200BN replace MR-J3-200BN-KM084U646 directly?

The base model alone should not be used to confirm compatibility. The complete KM084U646 suffix, JUKI part number 40104696, machine model, Y-axis application, connectors, and original nameplate should all be checked before replacement.

Q4: What problems may indicate a Y-axis servo drive fault?

Possible symptoms include servo alarms, inability to enable the Y axis, abnormal movement, intermittent machine stopping, positioning instability, communication faults, or complete loss of Y-axis motion. Motor, cable, power, and mechanical problems should also be inspected.

Q5: What information is needed for quotation?

Please provide 40104696, MR-J3-200BN-KM084U646, machine model, required quantity, preferred condition, destination country, and a clear photo of the original amplifier nameplate. This information helps us confirm the correct part before quotation.

III. Contact Us

Contact Us

Looking for a JUKI 40104696 MR-J3-200BN-KM084U646 2kW Y Servo Amplifier for your FX-3R or FX-3RA SMT machine?

Send us your part number, complete servo model, machine model, quantity, and original nameplate photo for compatibility confirmation and quotation.

We supply SMT machine parts for equipment maintenance, production-line repair, spare-parts inventory, and machine refurbishment requirements.

For faster service, please include:

Part Number: 40104696
Model: MR-J3-200BN-KM084U646
Machine: JUKI FX-3R / FX-3RA
Application: Y Axis
Capacity: 2kW
Quantity: Required Quantity

Contact us for availability, condition options, lead time, packing, and quotation.