Bernina 770 QE Manual page 51

Sewing preparation
> Pull the thread into the slot (2) from the left.
2
> Pull the thread to the right under the spring (3), then lead the thread under the two thread guides (4)
and pull upwards.
4
3
> When inserting into the machine, hold the bobbin case so the thread guide (5) points upwards.
5
> Insert the bobbin case.
> Press onto the center of the bobbin case until it engages.
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