TROUBLESHOOTINGA-10Incorrect thread tension■ Symptoms• Symptom 1: The lower thread is visible from the upper side of the fabric.• Symptom 2: The upper thread appears as a straight line on the upper side of the fabric.• Symptom 3: The upper thread is visible from the lower side of the fabric.• Symptom 4: The lower thread appears as a straight line on the lower side of the fabric.• Symptom 5: The stitching on the lower side of the fabric is loose or has slack.■ Cause/Remedy□ Cause 1The machine is not correctly threaded.The lower threading is incorrect.Adjust the upper thread tension and then refer to “Upper Thread is Too Tight” on page S-12.The upper threading is incorrect.Adjust the upper thread tension and then refer to “Tangled thread on wrong side of fabric” on page A-8 to correctthe upper threading.□ Cause 2A needle and thread appropriate for the fabric are not being used.The sewing machine needle that should be used depends on the type of fabric sewn and the thread thickness.If a needle and thread appropriate for the fabric are not being used, the thread tension will not be adjustedcorrectly, causing wrinkles in the fabric or skipped stitches.* Refer to “Fabric/Thread/Needle Combinations” on page B-49 to check that a needle and thread are appropriate for thefabric being used.□ Cause 3An appropriate upper tension is not selected.Adjust the upper thread tension to select an appropriate thread tension.The appropriate thread tension differs according to the type of fabric and thread being used.* Adjust the thread tension while test sewing on a piece of scrap fabric that is the same as that used in your project.* When the lower thread is visible on the upper sideof the fabric. Set the upper thread tension to a lowernumber. (Loosen the thread tension.)* When the upper thread is visible on the lower sideof the fabric. Set the upper thread tension to a highernumber. (Tighten the thread tension.)□ Symptom 1/2 □ Symptom 3/4a Lower side of fabricb Lower thread visible onupper side of fabricc Upper threadd Upper side of fabrice Lower threadf Upper thread visible fromlower side of fabricNote• If the upper threading and lower threading are incorrect, the thread tension cannot be adjustedcorrectly, even by adjusting the upper thread tension. Check the upper threading and lower threadingfirst, and then adjust the thread tension.
