my singer 7442 won't pick up the bobbin thread,an the needle bar moves funn?

Hi ,this machine has hardly been used,an now it won't pick up the bobbin thread,an the needle bar sort of wobbles when you turn it on. I have re thread every part several times,changed the needle 3 x,checked the bobbin case for dust etc.. ,nothing helps. can you help me.Sew teck wants 89.00 to set timing.Can I set timing myself? I won't spend 89.00 on this machine,I would just donate it to a school that teaches sew repair.