Another possibility is that the shuttle has been dislodged, so give the area under the needle plate (=throat plate) a good cleaning and make sure the shuttle assembly is installed correctly.
If it's not, and you've got a clean machine with a new, undamaged needle, fully in the needle clamp and right way around, tension set to about 3, it's probably time for a trip to the sewing machine shop. The timing may be off, or the sewing hook may be broken, or you've got another mechanical problem.
are you turning the wheel the correct way and not backwards- I have done this myself, try giving it a little more thread and slack, watch the keepers go around as they are supposed to catch it
I have a singer sewing machine. It is a sew mate 5400. I cannot get it to grab the bobbin thread.
It was working just fine before, and this is the first time I've had this problem. Before you ask, yes the needle is in correctly (they only 'fit' if it's put in correctly, this machine literally will not let you put the needle in if it's facing the wrong way), yes I've tried other needles, yes they are the correct needles. Yes my bobbin is in correctly, and the machine is threaded correctly. I even dug out the manual and followed the threading process step by step exactly as the manual said. The needle goes down but the thread does not loop around the bobbin to catch the bobbin thread. It just comes right back out without doing anything really.
Is this a machine error or user error? Does anyone have any suggestions, or know something I may have overlooked?
The manual has step by step instructions to place the bobbin, thread the machine, and pull up the bobbin thread up, but no information or troubleshooting ideas if it fails to catch the bobbin thread. Please help.