When I press on the pedal the machine just makes a 'vruuuuuu' sound, and when it sews it tangles around the bobbin! It also does not pick up the bobbin thread

The vruuuuu sound could be the motor racing but it is not turning the gears. Check to make sure the bobbin winder is disengaged--an activated bobbin winder will prevent the gears and the needle from moving. Could be a belt is broken or stretched so it is slipping instead of turning the gears.

Check to be sure the correct needle is being used for the machine. When threading the upper thread, RAISE the presser foot first so the thread will seat properly in the tension disk.

1. The bobbin may be in backwards.
2. The bobbin thread & top thread need to be pulled to the back before starting the stitching
3. You need a ballpoint rather than universal needle to sew on t-shirt knits.
4. the needle is in the machine backwards
5. Make sure the needle is the correct one for the fabric being sewed
6. Needle inserted wrong in the needle holder
7. Damaged needle
8. Warped bobbin
9.First make sure the bobbin-winding spindle (located on top of your machine) has been pushed back to the left for sewing.
10.If it is not in the correct position, the needle will not go down and pick-up your bobbin thread.
11.Next make sure your needle is inserted correctly, with the flat side facing back.
12.Also, make sure your bobbin is in correctly
13.the upper tension disks of your machine are threaded correctly.
14.Make sure the presser foot is up when seating the thread through the upper tension.
15.Turn the handwheel towards you only and hold the needle thread lightly.
16.could be a timing problem
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