Something here may help:
How to Sew Pin Tucks Threads
Try removing the top threads from the machine. ALWAYS RAISE the presser foot and rethread both threads. Could be possible your threads were not seated in the tension disks.
When they serviced the machine, did they include stitch samples when the machine was returned to you? If so, then it would appear the machine was working properly at the time. Verify that you are threading the machine correctly--not skipping any thread guides along the way, inserting the bobbin turning the wrong direction. Verify everything you are doing with the manual.
My suggestion:
Take it back to the technician(s) who worked on it and request that he or she address the problem. Telling you to buy a new machine is not sufficient answer. They charged you a service call and did not repair it. If there are parts or more repairs required, they should be able to tell you what it would take and cost to accomplish having a working machine. From that point, you should be able to make your own judgment whether fixing it is economical or buying new is the better answer.
There are some things you can try but without knowing more of what the machine is doing, recommendations are difficult.
For one: remove the top thread from the machine and ALWAYS RAISE the presser foot when threading the top thread.
Install a brand new needle and verify that it is installed facing the correct direction.
Set the top tension to the midway point--this can always be tweaked.
If it is actually a tension issue, the following web sites may be helpful. Check how your top and bobbin tensions appear. If the bobbin thread still appears loose, the bobbin tension may need tightening. (The bobbin tension should have been properly set with the part was replaced.) You can try tightening the bobbin tension by turning the screw. CAUTION: mark the beginning point of the screw BEFORE making any adjustments so you can return it to the original point if things don't work. AND, turn only 1/8 to 1/4 of a turn at a time and recheck the stitch quality between turns.
Understanding Thread Tension Threads
Manual:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwi1wKyD9__TAhVO7GMKHVOcC7sQFggmMAA&url=http%3A%2F%2Fjanome.com%2Fsiteassets%2Fsupport%2Fmanuals%2Fretired%2Fcomputer%2Finst-book-mc4000.pdf&usg=AFQjCNHXP9z7dWGFaVchzjicsdfYtEBAEA
I will need more information to answer this question. This machine may need trained service technician to look at it. have them offer an estimate for the repair, it's a good idea to have it cleaned and adjusted as well.
Cheers,
Embroidery Services
San Diego, CA
Most any sewing machine (zig-zag capable is probably better but a straight stitch can be used) should be able to do manual embroidery/applique. The lady in the video states she's using an embroidery foot, but in reality a darning or free motion presser foot may be better. Most embroidery presser feet actually press down on the fabric making it difficult to move the fabric manually. A darning or free motion presser foot is actually shorter and allows space for the fabric to move freely.Don't forget to lower the feed dogs!!!Lots of web sites and videos on the internet! How To Do Free Hand Machine Embroidery https://www.youtube.com/watch?v=6vAmmmNbL88..
Remove the upper thread completely. Install a brand new needle. RAISE the presser foot and rethread from the beginning. Confirm with the owner's manual the threading pathway is correct. Set the upper tension to the midway point between the high & low number. Retest.
Correct tension is when the upper and bobbin threads meet in the middle of the fabric. If bobbin thread is showing on the top of the fabric, loosen the upper tension. If upper thread is showing under the fabric, tighten the upper tension.
Make sure the thread, needle, and fabric are compatible.
All About Needles
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Most machines require some sort of foot or knee pedal. There are, of course, treadle machines that you actually "pump" with your feet. There are also hand-crank machines available. Some of the newer machines that have a free motion capability can be set to stitch only when the fabric is moved under the lens, however, that is probably best only for free motion quilting and not for actually stitching seams, etc.If your machine is lacking the foot pedal, check to see if a replacement can be found. Frequently, a sewing repair shop can either locate a generic or wire one for your machine.Here's a manual for your machine:https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=0ahUKEwi-uNjQq5PLAhUC6mMKHfDkBDgQFghGMAc&url=http%3A%2F%2Fjanome.com%2Fsiteassets%2Fsupport%2Fmanuals%2Fretired%2Fcomputer%2Finst-book-mc4000.pdf&usg=AFQjCNHXP9z7dWGFaVchzjicsdfYtEBAEA...
2 things must do:
You have to use the buttonhole foot.
You have to pull down the lever to the lowest position (just left of needle bar/ presser bar up in machine.)
Set to buttonhole. After each buttonhole, be sure to change off the buttonhole then reset to buttonhole to reset the buttonhole to the beginning
If you are experiencing stitching problems with your sewing machine or serger, the first thing to do is install a brand-new needle. A bent, dull, or defective needle is a frequent cause of sewing machine and serger problems. Also, replace the needle often. The needle wears with use, is the easiest thing to try when troubleshooting, but is the least expensive part in a sewing machine (an inexpensive fix for a frustrating experience)..
