My janome machine sews on the same spot, the material does not move. I have moved the feeder foot but nothing happens.Sometimes the feeder foot stays down.Idont have a manual for this machine.Igot it as a present from my daughter from qvc.

If your Janome Jem Platinum sewing machine is displaying an "CO" error code, it means that the machine's needle bar is obstructed and cannot move up and down properly. To resolve this issue, you can try the following steps:

1. Turn off the machine and unplug it from the power source.
2. Open the needle plate and inspect the area around the needle bar to see if there is any thread, fabric, or other material

Have you tried turning the handwheel and using the foot control at the same time just to get it moving if its humming when you put your foot down its trying to go sometimes a little help to get it going helps it might need some oil or its got a dry spot from being stored give it a go and let me know how you got on. Ron

Make sure the feed dogs have not been dropped, ie for darning or free motion quilting. Also, make sure the stitch length is set high enough to actually create a forward stitch.

If, as you have noted, this is a mechanical machine, my suspicion is that it has not been cleaned and oiled recently and possibly the old oil has solidified preventing the parts from moving.

Here is a web site that may be helpful:
Janome Domestic Sewing Machine Maintenance

You may not need to go to the extent of removing parts and soaking them in cleaner, but certainly cleaning the dust & lint and then oiling with a fresh good quality sewing machine oil may be the ticket to your resolution.

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sounds like the foot tension needs to be adjusted.

We have a sewing machine that was manufactured by Janome. It is a New Home Deluxe Model. It has very little travel on the pressure foot itself versus other sewing machines. I have learned just by using this machine.... If you need to get the foot up high...all you have to do is reach through and grab the pressure foot and while picking it up(not the lever but the foot itself) turn it clockwise just a touch and it will stay up plenty far enough to get larger or thicker material under it to sew. I hope this helps. Thanks and remember "Be Easy!" Neighborsboy

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There is probably a bad connection in your foot pedal. Try moving it around with your hands at the contact points while pressing to activate. If it goes when you are shifting its position then it needs to be fixed or replaced.

the teeth (feed dogs) must be up enough so they can move the fabric with the help of the presser foot (or all purpose foot)

I think you may have to careful clean everything and check you havn't dropped feed dogs or changed a setting. I don't really know what you mean by the foot getting stuck, but if the feed dogs ( moving part under the cloth) are down than the cloth can't move. Also, the pressure of the foot may be too high; this can also happen accidently while cleaning.
Get a manual ( sewingmanuals.com) and double check everything. Also, check there is no thread in the thread guides as this may have been your original problem. pull a thread towards to needle

Are the feed dogs engaged? Janomes usually have a feed dog sliding switch, either on the back of the sewing machine at the bottom, or behind the accessory case. Be sure the check it out. Hope this helps!