If your decorative stitches aren't working, the grease on the cam stack has likely hardened. Clean it with a cotton swab and apply fresh electronic grease. Timing and Tension Calibration
The single most common issue with the Optima 610 is timing drift. Because it’s a high-speed machine, the relationship between the needle and the rotary hook must be precise. If this timing is off by even 0.5mm, you will get skipped stitches or needle breakage. The service manual provides step-by-step timing alignment, often requiring specialized tools (like a timing gauge) that are also listed in the manual’s appendix. husqvarna optima 610 service manual
Detailed steps for removing machine covers and the accessory box to access internal gears. If your decorative stitches aren't working, the grease