Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I confess that I cannot quite picture what 'the needle shakes' and 'no longer sews' could mean exactly.
Does the needle still descend into the cloth?
Is it that it still goes into the cloth, but the top thread and the bobbin thread no longer combine to make stitching?
I would advise you to try a reset of the machine, then conclude (after following instructions as to threading the top thread, threading the bobbin thread, etc.) that the machine has proved defective from manufacturer within warranty, and return it to Brother USA (or, a local Brother-authorized repair center) for repairing within warranty.
(To locate Brother-authorized service shops for this type of machine, in your region, please tell me what region you are in, e.g. by zip code, or by town/city and state/region.)
For reference, the warranty statement is here: