I have a Juki8700 it does not seem to be feeding the fabric thru on the feed dog

Have you got a tangle under your fabric? If so, release the fabric and rethread your machine, making sure the foot is up during threading. Otherwise check the feed dog under the foot. There's usually a switch somewhere that brings the feed dog up or down. If it's down the fabric won't feed. Another point, what type of fabric are you sewing. If it's leather or leatherette you'll need to use a roller foot. Hope this helps.

Is your presser foot down? Do your feed dogs go down? If they do move the lever to the up position. The feed dogs are what feeds the fabric thru the machine.

Check that the stitch length is set to make ~10 stitches per inch. This stitch is long enough to actually move the fabric. If the stitch length is set too short, the fabric will stay barely move and the needle will stitch almost in place.

Check that the feed dogs have not been dropped for darning or free motion quilting. In this position, they do not rise and are, therefore, unable to contact the fabric to pull it through the machine.

With the presser foot raised and using no fabric, hand rotate the handwheel and watch if the feed dogs actually drop down below the needle plate, move toward the front of the machine, then rise above the needle plate, and move toward the back of the machine. If the feed dogs are moving in this manner, then they are functioning properly.

Is there lint or gunk stuck in the feed dogs? This will restrict the ability of the feed dogs to grip the fabric.

Are the feed dogs worn? Are the little teeth worn so there are no sharp points?

What type fabric are you using? If it is very light-weight or slick fabric, the feed dogs will have a difficult time gripping the fabric. Most machines have a presser foot pressure adjustment so that more pressure is applied between the presser foot and the feed dogs. Consult your Owner's Manual. The adjustment is usually a dial either on the left side of the machine, on the front of the machine located above the needle bar, or on vintage machines it is usually a skrew located under the top lid above the needle bar.

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Without fabric in your machine and with the presser foot raised, do the feed dogs move front->back? Are the feed dogs in the raised position? Is the stitch length at a 10-12 stitch per inch setting so that the fabric actually moves (try increasing the stitch length to see if it makes a difference)?

Does your machine have a presser foot pressure adjustment? If you are sewing light weight fabric, the pressure may need to increased so there is more pressure applied by the presser foot to the feed dogs. You can also try adding a strip of tear-away or wash-away stabilizer to the underside of the fabric as you stitch so the feed dogs have something to grip.

Are the tips of the feed dogs rounded? Could be worn and need replacement.

If the feed dogs are not moving, how long has it been since the machine was cleaned and oiled?

It was working now it seems to be frozen the needle part wont move

If the feed dogs remain below the needle plate, and the feed dog lever does not activate them, then perhaps something is disconnected in the feed dog mechanism. The feed dogs should rise when stitching begins.

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the needle only sews,, it's the feed dogs in the needle plate area that feed the fabric thru the machine, if the feed dogs are in the up position then the machine will sew, if the machine is not sewing then the feed dogs need to be checked to see if the feed dog lever is up or down, look in the manual to see where the lever is and check it, if the lever up the then feed dogs will need to be checked to see if there is something's wrong with them at a sewing machine repair shop.

have you checked the presser foot to see if the presser foot is holding
the fabric against the feed dogs so they can move the fabric thru to
be sewn by the needle?

the feed dogs are what move the fabric thru the machine to sew it
if the feed dogs are not working, then they need to be checked
to see if they have some loose or broken or need to be retimed

what is the name of the machine?
do you want a manual?
the feed dogs are what move the fabric thru the machine, the presser foot only hold the fabric against the feed dogs so the feed dogs can move the fabric
the feed dogs in the needle plate area should be up

Have you changed the stitch length selector to zero ? If there is no lint trapped under the needle plate between the feed teeth, then the length selector is likely set too small,.

adjust your feed dog hight. manual shows u how