Stop and identify the symptom
Uneven stitches can mean several different things: stitches of different lengths, loops beneath the fabric, skipped stitches or a seam that pulls the fabric into wrinkles. Stop sewing and examine both sides of a small sample. Describe what you see before changing any settings. A clear description helps you decide which basic check to make next.
Use your machine manual throughout the checks. These steps cover ordinary operator tasks only. Do not open electrical covers, adjust internal timing or attempt motor repairs. If the machine makes an unusual noise, smells hot, has a damaged cable or repeatedly strikes the needle plate, stop using it and seek qualified help.
Recheck the threading
Incorrect threading is a useful early check when a seam develops loops or loose stitches. Stop the machine before handling the thread path. Rethread the upper thread according to your manual, including its instructions for presser foot and needle position. Confirm that the thread passes through every required guide and the take-up lever.
Check that the bobbin is the correct type for the machine and is inserted in the direction shown in the manual. Follow the stated path into the bobbin tension guide. A bobbin that fits loosely or has thread wound unevenly can cause difficulties. Do not turn bobbin-case adjustment screws as a beginner troubleshooting step.
Check the needle, fabric and feeding
Switch off and unplug the machine before inspecting or changing the needle or removing lint. Fit a new compatible needle if the existing one may be bent or damaged. Insert it fully in the correct direction and secure it as instructed. Match the needle type and size to the practice fabric and thread.
Place two layers of stable woven scrap under the presser foot. Lower the foot and sew slowly without pushing or pulling the fabric. Check that feed dogs are in the position required for ordinary sewing. If your machine has different feeding modes, use the manual to restore the normal sewing setting.
Test carefully and know when to stop
Inspect the test seam after checking threading and the needle. If your manual recommends an upper-thread tension adjustment for the symptom, make a small change and test again. Note the original setting so you can return to it. Avoid changing tension, stitch length, needle and thread all at once.
Remove loose lint only from areas the manual identifies as accessible to the user, with the machine switched off and unplugged. Use the recommended cleaning method; do not add oil unless the manual specifies it. If the same problem continues after basic checks, retain the sample and ask a qualified technician for help.
