Uneven feed

A needle that clicks against the plate or skips stitches is often bent from nicking a pin or age. Replace it immediately, since a bent needle can also throw off hook timing.

A machine that locks up, often with a knot of thread underneath, usually means the bobbin is threaded backward or wound around the case. Clear the jam by hand, rewind the bobbin, and rethread from scratch.

A snapped needle usually means fabric was pulled while sewing, a pin was hit, or the needle was too fine for the fabric. Slow down, clear pins from the stitch path, and size up the needle.

Too much foot pressure flattens pile and stretches knits; too little lets fabric wander or fail to feed. Adjust the pressure dial to suit the fabric weight, lowering it for delicate or bulky fabrics.

Persistent skipped stitches across all needle types and tensions, especially after a hard jam or drop, points to hook timing out of sync with the needle. This needs professional service, not a home fix.