Brother International PR-620 Users Manual - English - Page 223

APPENDIX Symptom Although the thread is not broken, a broken thread error occurs and the machine stops. There are needle cuts or holes in the garment. There is puckering in the fabric. The LCD cannot be read. Probable Cause If the thread breakage sensor in the thread tension disc of the thread tension knobs cannot detect that the thread is being fed, even if the machine is running, a broken thread error occurs and the machine is stopped. If the thread came out of the thread tension disc, even though the thread is not broken, the machine detects that the thread is not being fed and stops. The needle is dull. The fabric is too delicate. The thread tension is too tight. The framing tension of the fabric is incorrect. The column stitches are too long. The needle is dull. The design density is too heavy. Remedy Correctly pass the thread through the thread tension disc. If the broken thread error occurs after the machine is rethreaded, the sensor may be damaged. Consult your nearest authorized dealer. Replace the needle. Dull needles have a difficult time passing through the garment, causing fabrics to tear. The simple penetration of the needle could damage delicate fabrics. Use stabilizer on top of fabric. Adjust the tension according to the type of fabric and thread being used. Polyester thread will stretch during sewing especially if the tensions are set too high. After the stitching is complete, the thread returns to its original strength, causing puckers in the fabric. Tightly frame non-stretchable, woven fabrics. Loose framing will cause the fabric to bunch up under the stitching. Tautly frame soft knits using a stable backing. Overstretching the garment will cause it to look puckered when the frame is removed. Re-digitize the design with fill stitching or with multiple rows of column stitching. Dull needles push fabric down and damage material. Replace the needle. Too many stitches in an area pull fabric, causing it to pucker. Slightly decrease the design density by 5% to 10%. The LCD contrast is incorrect. Adjust the contrast on the LCD. Reference Page p.37 p.15, 63 p.167 p.86 p.166 p.15, 63 p.142 CAUTION ● This machine is equipped with a thread detecting mechanism. If the machine is not threaded with the upper thread, the machine will not operate correctly, even if the start/stop button is pressed after unlocking the machine. ● If the machine suddenly stops: - Turn off the machine, and unplug the power cord. - Restart the machine with the correct operating procedure. Refer to page 20. 206