Janome JEM Gold 660 Service Manual

The Janome JEM Gold 660 is a compact, lightweight sewing machine designed for quilters and crafters. It features 66 built-in stitches, automatic needle threader, built-in thread cutter, 7-piece feed dog system, superior needle plate, and advanced stitch quality. This service manual provides comprehensive technical information for maintenance, troubleshooting, and repair procedures. Below are key sections for specifications, maintenance, disassembly, troubleshooting, and parts identification.

1. Technical Specifications 2. Safety Precautions 3. Maintenance Procedures 4. Disassembly Instructions 5. Electrical System 6. Mechanical Components 7. Troubleshooting Guide 8. Parts Identification 9. Adjustment Procedures 10. Lubrication Points 11. Service Contacts

Technical Specifications

Key technical data and performance specifications for the Janome JEM Gold 660 sewing machine.

Specification	Description
Machine Type	Compact Computerized Sewing Machine
Built-in Stitches	66 stitches including utility, decorative, and quilting stitches
Stitch Width	Up to 7mm
Stitch Length	Up to 5mm
Buttonhole Styles	6 one-step automatic buttonholes
Needle Threader	Automatic built-in
Thread Cutter	Built-in automatic
Presser Feet	7 included (zigzag, zipper, satin stitch, etc.)
Feed Dog System	7-piece drop feed
Motor Power	DC Servo Motor

Safety Precautions

Essential safety guidelines for service technicians and users.

Always unplug machine before performing any maintenance or repair.
Use only genuine Janome replacement parts.
Wear safety glasses when working with springs or small components.
Keep work area clean and well-lit.
Follow electrostatic discharge (ESD) precautions when handling electronic components.

WARNING! High voltage present in power supply unit. Only qualified technicians should service electrical components.

Maintenance Procedures

Routine maintenance schedule and procedures for optimal performance.

Daily cleaning: Remove lint and dust from bobbin area and feed dogs.
Weekly oiling: Apply sewing machine oil to designated points.
Monthly inspection: Check needle bar, hook, and timing.
Annual service: Complete disassembly and thorough cleaning.
Needle replacement: Replace needle after every 8 hours of sewing.

CAUTION! Use only high-quality sewing machine oil. Do not use household oils.

Disassembly Instructions

External Covers: Remove 6 screws from top cover, 4 from side panels.
Needle Bar Assembly: Remove presser foot, needle plate, and needle bar cover.
Hook Assembly: Remove bobbin case and hook race ring.
Motor Assembly: Disconnect power, remove motor mounting screws.
Circuit Board: Remove main board cover and disconnect all connectors.
Feed Mechanism: Remove feed dog cover and feed dog assembly.
Handwheel: Remove set screw and pull handwheel off shaft.

Electrical System

Electrical components and circuit diagrams for troubleshooting.

Main Components: Power supply board, main control board, motor control board, foot controller, LCD display.

Voltage: 120V AC, 60Hz. Motor: DC servo motor with speed control. Display: Backlit LCD with stitch selection indicators. Connectors: 8-pin main board connector, 4-pin motor connector, 3-pin foot control connector.

Mechanical Components

Detailed mechanical assembly and component specifications.

Upper Shaft Assembly: Includes needle bar, presser bar, and take-up lever.
Lower Shaft Assembly: Hook drive and bobbin mechanism.
Feed Mechanism: 7-piece feed dog system with adjustable height.
Stitch Selection: Electronic stitch selection with mechanical engagement.
Tension Assembly: Upper and lower thread tension mechanisms.

Tip: Mark all components before disassembly for proper reassembly.

Troubleshooting Guide

Common problems and solutions for the JEM Gold 660.

Symptom	Possible Cause	Corrective Action
Machine won't start	Power cord, foot control, main board	Check power connection; test foot control; inspect main board fuses.
Poor stitch quality	Timing, tension, needle	Check hook timing; adjust thread tension; replace needle.
Thread breaking	Tension, burrs, threading	Reduce upper tension; check for burrs on needle plate; rethread properly.
Skip stitches	Needle, timing, presser foot	Replace needle; check hook to needle timing; ensure proper presser foot pressure.
Motor runs but no stitch	Drive belt, handwheel	Check drive belt tension; ensure handwheel is engaged.

Reset: Unplug machine for 30 seconds to reset electronic controls.

Parts Identification

Complete parts list with reference numbers and descriptions.

Part Number	Description	Qty
J660-001	Needle Bar Assembly	1
J660-002	Hook Assembly Complete	1
J660-003	Upper Shaft	1
J660-004	Lower Shaft	1
J660-005	Feed Dog Assembly	1
J660-006	Main Circuit Board	1
J660-007	DC Servo Motor	1
J660-008	Power Supply Board	1
J660-009	LCD Display Module	1
J660-010	Foot Controller Assembly	1

Adjustment Procedures

Critical adjustments for proper machine operation.

Hook Timing: Adjust so hook point passes needle eye 2.0-2.5mm above needle eye.
Needle Bar Height: Set so needle eye is 10.5mm above needle plate when at lowest position.
Feed Dog Height: Adjust so feed dogs rise 0.8mm above needle plate.
Presser Foot Pressure: Adjust spring tension for different fabric types.
Thread Tension: Balance upper and lower tension for perfect stitches.

WARNING! Make small adjustments and test thoroughly after each change.

Lubrication Points

Designated oiling points and lubrication schedule.

Oil Points: Upper shaft bearings, lower shaft bearings, hook race, feed dog mechanism, needle bar bushings.

CAUTION! Use only Janome sewing machine oil. Over-oiling can damage electronic components.

Service Contacts

Janome America Service Centers and technical support information.

Janome America, Inc. 10 Industrial Avenue, Mahwah, NJ 07430. Technical Support: 1-800-631-0183. Service Centers: Nationwide authorized service locations. For parts ordering and technical assistance, visit www.janome.com or contact your local authorized Janome dealer.