I need a schematic for a Brother 6700 embroidery machine. I cleaned the bobbin case and around it and now the machine is making lots of noise.

Your bobbin is too short. The correct bobbin must be even with the bobbin case. If it is the bobbin case that is moving around then you must adjust the inner rotary hook bracket assy. It must allow the thread to move between the corner (near screw) and the bobbin casing. Rotate the hand wheel towards you to make sure the thread fits between the corner and the casing. Make it as tight as possible without a snag taking place.

Usually this is a tension problem. On mechanical machines, you'd adjust the dial, or possibly even the bobbin tension. But on a computer machine, I don't know how you set the upper tension, sorry to say.

Sometimes it can help to unthread and rethread a machine, and I don't know why it sometimes works, but it's a simple thing to try.

But if the upper tension isn't set correctly for the work being done or if the tension mechanism, however that's handled on a computer machine, isn't working correctly, this is what happens. Bird's nest is a good way to describe it.

Sometimes lint built up in the bobbin case can cause this symptom too, but I'd assume you keep this area clean. One reason I haven't yet invested in a computer machine is because problems like this often don't have such simple solutions as on the mechanical machines.

I was just telling someone else that I recently learned from the sewing goddesses that be (at my local Hancock's Fabric Store)--that--you have to use the right bobbin. I mean plastic if your machine came with plastic. Class 65/ 55 (I think those are the numbers) as to match the machine's design. Use metal if your machine came with metal.

the bobbin case is weighted "just so" in order to be sure to run smoothly with the particular bobbin type.

Of course, the top tension and bottom tensions must be checked as well.

You could have some stuff stuck in the bobbin encasing thingy (it has two black tapered lever arms that you can move about 15 degrees to the outside and the case encasement pops out).

I agree with sylviaivie about find another repairman, they are suppose
to guarantee the work they do.
when the upper shaft is replaced & then the machine is retimed
the machine should work just fine.
but just don't take it back to that man to be repaired
here is a tip if it happens again,,
always try to cut the top thread first,
& turn the machine up on it's back to access the bottom cover
take the cover off the bottom to get access to the bobbin thread
where you can cut the bobbin thread
then you should be able to get the needle out without breaking it &
damaging the upper shaft, replace the needle & make sure
that the thread is good quality & not knotty, clean out the bobbin area of lint or thread
always change the needle on the embroidery machine every project
make sure the bobbin area is kept clean of lint or thread
clean under the needle plate at least once a week for lint if you
embroidery everyday or just often

With the embroidering, some of the bobbin thread is SUPPOSED to show on the top of your embroidery-the machine isn't doing anything incorrectly. You'll need to thread your bobbin with the same thread as you are using with the top. I had the same "problem" when I first got the machine and took it to a wonderful local technician whose helped me with a lot of things who informed me that this is perfectly normal on embroidery machines.

make sure the bobbin thread is wound and installed correctly
remove tangled thread and clean lint out from under feed plate
clean and remove shuttle to clean out area with lint brush
inspect bobbin for burs and scratches...make sure when reinstalling shuttle and bobbin that it rotates freely
hope this helps

The only place you can opil an ultim is inside the bobbin case and around the bushings in the front end. Do a search for Anns fix it and you will find more than you will ever need for these machines

Make sure you're using the correct foot for the stitch. Is this during sewing or embroidery? Take off the bobbin plate using the screwdriver and remove the bobbin. Make sure everything is clean under and around the shuttle. If you've ever broken a needle the tip might have fallen down into the mechanism and occasionally be jamming it.

I would take it to a mechanic.

If you can return the machine and get your money back. this machine is nothing but TROUBLE and will continue to have problems.