Husqvarna 400 / 500 Sewing Machine Service Manual (P/N 412 39 91-45 E)

This 60-page official Husqvarna Sewing Machines AB publication (P/N 412 39 91-45 E, printed in Sweden) serves as the primary factory reference for the original 1993–1995 Husqvarna 400 and 500 computerized sewing machines. Written explicitly for workshop technicians, mechanics, and capable DIYers, the documentation covers essential maintenance, interface navigation, and programmed operation parameters.

• Details setup procedures, including foot control integration, threading protocols, bobbin winding, and thread tension calibration.
• Contains 12 technical diagrams mapping out machine nomenclature, accessory tray layouts, and buttonhole sensor integration.
• Outlines routine workshop maintenance schedules and component tolerances.

What the Manual Documents

This instruction and service publication organizes the operational sequences of the 400 and 500 series into practical, descriptive chapters. The documentation walks you through initial machine setup—from unpacking and power supply connectivity to advanced memory programming and utility stitch selection. Detailed sections address routine workshop maintenance tasks. These include needle replacement protocols, stitch plate removal, and deep cleaning of the bobbin area to maintain factory precision tolerances. Before initiating any internal maintenance or removing protective housing, always verify the machine is fully disconnected from its primary power source to prevent accidental motor engagement. Furthermore, the manual provides specific guidance for specialized sewing techniques. You will find exact parameter settings for quilting, buttonhole programming, zipper insertion, and decorative monogramming.

Specification Highlights

Technical data within the publication defines the operational boundaries for both models. For workspace planning, the machine footprint is documented at 47 cm by 22 cm. Under factory conditions, the maximum sewing throughput reaches 1100 stitches per minute. The stitch width capability for standard operations is rated at 16 mm, and the mechanical precision is maintained within strict +/- 0.5 mm parameters.