The Singer 6105 is a versatile sewing machine designed for home use, featuring multiple stitch patterns, adjustable stitch length and width, built-in buttonholer, free arm capability, and a drop feed for darning and embroidery. This service manual provides detailed information for technicians on safety procedures, machine specifications, disassembly, troubleshooting, lubrication, and reassembly. Below are key sections covering all aspects of service and maintenance.
Before servicing, always unplug the machine from the electrical outlet. Work on a clean, well-lit surface. Use proper tools to avoid damage to components.
WARNING! Failure to observe these precautions may result in electric shock, injury, or damage to the machine.
Standard sewing machine toolkit plus specific items for the 6105 model.
| Tool | Purpose |
|---|---|
| Small Phillips Screwdriver | Removing case screws |
| Flat-head Screwdriver | Prying clips, adjusting tension discs |
| Hex Wrench Set (1.5mm - 4mm) | Adjusting needle bar, hook timing |
| Needle Nose Pliers | Handling small springs and clips |
| Lint Brush | Cleaning internal lint |
| Machine Oil (Singer Brand) | Lubrication |
| Multimeter | Testing electrical continuity |
| Soft Cloth | Wiping components |
Key components on the exterior of the Singer 6105.
Primary internal assemblies: Needle Bar Assembly, Hook Assembly, Feed Dog Assembly, Motor & Drive Train, Main Shaft, Tension Assembly, Electronic Control Board.
Drive System: Main shaft driven by motor via belt; converts rotary motion to needle bar and feed dog movements.
Timing Relationship: Critical alignment between needle bar (top dead center) and hook point for loop formation.
Step-by-step guide to safely disassemble the machine for service.
CAUTION! Keep screws and small parts organized in labeled containers.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Machine does not run | No power, faulty foot control, motor issue | Check power outlet, test foot control with multimeter, inspect motor brushes. |
| Poor stitch formation (skipping) | Needle bent, incorrect timing, hook damaged | Replace needle, check and adjust needle bar/hook timing, inspect hook for burrs. |
| Thread bunching underneath | Incorrect bobbin threading, tension too loose | Rethread bobbin, increase upper tension, clean tension discs. |
| Unusual noise | Lack of oil, lint buildup, foreign object | Clean and oil machine, remove lint from hook area, inspect for obstructions. |
| Feed dogs not moving | Drop feed engaged, broken parts | Disengage drop feed lever, inspect feed dog mechanism for wear or breakage. |
| Buttonhole not forming correctly | Stitch width setting, sensor issue | Adjust stitch width to recommended setting, check buttonhole sensor connection. |
Testing the power supply, foot controller, motor, and control board.
Tip: Refer to the wiring diagram in the Parts List section for connection details.
Use only Singer recommended sewing machine oil.
WARNING! Over-oiling can attract lint and cause gumming. Wipe excess oil.
Reverse of disassembly, paying attention to alignments and torque.
Critical adjustments for optimal performance.
Needle Bar Height: With needle at highest position, the eye should be approximately 1mm above the top of the hook.
Hook Timing: The point of the hook should pass through the center of the needle eye when the needle has descended about 2mm from its highest point.
Feed Dog Height: At highest position, teeth should protrude about 0.8mm above the needle plate.
Presser Foot Pressure: Adjust via spring tension screw for even fabric feed.
Reference for ordering replacement parts. Key part numbers:
For complete exploded-view diagrams and the full parts list, contact Singer Authorized Service Centers or visit the official parts website.