Brother International SB8000 Operation Manual - Page 199

Symptom Probable Cause Remedy Reference The bobbin thread is incorrectly installed. Correctly install the bobbin thread. page 29 The lower thread is tangled or breaks. The bobbin is scratched or does not rotate smoothly, or has a burr on it. The thread is tangled. Replace the bobbin. Remove the tangled thread and clean the race. - page 184 A bobbin designed specifically for this machine is not used. Incorrect bobbins will not work properly. Only use a bobbin designed specifically for this machine. page 25 The upper thread was not threaded correctly. Correct the upper threading. page 31 The bobbin thread is incorrectly installed. Correctly install the bobbin thread. page 29 The thread tension is incorrect. The combination of fabric, thread and needle is not correct. The presser foot holder is incorrectly installed. Select a thread and needle that are appropriate for the type of fabric being sewn. Correctly install the presser foot holder. page 41 page 46 The thread tension is incorrect. Adjust the tension of the upper thread. A bobbin designed specifically for this machine is not used. Incorrect bobbins will not work properly. Only use a bobbin designed specifically for this machine. page 59 5 page 25 The upper thread was not threaded correctly, or the bobbin is incorrectly installed. Correctly thread the upper thread and correctly install the bobbin thread. page 29, page 31 The spool is incorrectly installed. Correctly install the spool. page 31 The fabric is wrinkled. The combination of fabric, thread and needle is not correct. Select a thread and needle that are appropriate for the type of fabric being sewn. The needle is bent or blunt. Replace the needle. page 41 page 42 If thin fabrics are being sewn, the Shorten the stitch length or sew with stitch is too long. stabilizer material under the fabric. page 59, page 66 The thread tension is incorrect. Adjust the tension of the upper thread. page 59 Troubleshooting 197