Unlock brothers LS2125i sewing machine

SOURCE: Brother XL-5130 Sewing Machine

Put the thread through one of the holes. Then put the bobbin on the spindle. Pull about 3 or 4 inches out of the hole and hold on to it. Start winding the bobbin. After about ten turns, or when the winding thread is secure, you can stop the machine and cut off this 3 or 4 inch tail. To insure that the thread winds up and down the bobbin and not off the top or bottom, there is probably a metal bobbin tension disk that the thread must pass around before it goes to the bobbin. It is probably on the left of the machine and may or may not be part of a thread guide. The thread must pass around this disk on its way to the bobbin in order to put tension on the thread so it will wind properly. If you can't find the disk, which is a small metal button or screw with some type of somewhat moveable spring cap, you can just get the thread to pass through your thumb and forefinger. Hold your hand 6 or 8 inches to the left of the bobbin and pass the thread between your thumb and forefinger so that it makes the thread go in a direct straight line to the bobbin. Pinch the thread only enough to keep it taught but not tight and let it flow through your finger to the bobbin. The thread should go up and down evenly on the bobbin. If not, move your hand up or down to position it so the thread will wind up and down smoothly. It will not be necessary to move your hand once you find the correct position needed for winding.

SOURCE: Brother Sewing Machine model:CS8150 bobbin thread problems

The top of the machine is not threaded correctly. First raise the presserfot then rethread the machine. Bottom looping is usually caused by a lack of top tension. There could allso be a bur on the hook.

SOURCE: Brother 2001 sewing and embroidery machine.

The fact that your machine is turning hard says you still have some thread inside the machine that is binding up and activating the safety device. It must turn easily before it will work properly again.
Sometimes the machine must be disassembled to remove these threads.
sewman7

SOURCE: while sewing the bobbin case moves, wheel locks up, needle locks

Im not sure if this will help but thought I would pass it along. My Pfaff 6122 tells me to check bobbin for thread unrolling clockwise before you place it back in the machine. I had mine turned to un roll counter clockwise, this is wrong, the bobbin will fall out when you pull on the thread while you are holding it in your hand. You may just keep putting it in backwards. Hope this works for you. J.R.

SOURCE: can't draw up the bobbin thread

Make sure you have enough of a "tail" from teh bobbin... Probably 4 inches or so before starting. If that doesn't work, check upper tension and needle is properly seated.

The needle drags the thread down and then starts back up causing a loop at the eye which a shuttle goes through and acrries the upper thread over the bobbin. The upper thread then drags the bobbing thread up.