We all have these occasionally! Our Bernina machines are mighty, but they need to know when to stop!
If the machine feels a resistance to the needle penetrating the fabric, more power is sent to the motor, and your machine goes into 'hammer mode' for a split second; this will usually allow you to carry on stitching. If the protective sensors read there is more resistance than there should be your machine stops allowing you to figure out what has happened without damaging the machine.
Learn to love the 'Cogs of Death'! It is your machine protecting itself.

While you now know not to panic, it’s likely that your machine has got mechanically jammed and you can check this immediately by attempting to turn the handwheel. If not jammed, just try re-starting the machine and hopefully the problem will be resolved.

If it doesn’t turn easily, DO NOT try to force it – you could cause expensive damage. Try removing the bobbin case and hook and see if this free’s-up the mechanism. Make sure there’s no thread trapped in the hook race or driver. If the machine is determinedly jammed, contact us.