Threads wont stitch - White Sewing Mighty Mender WW100 Mechanical Sewing Machine

If it doesnt bring bottom thread to top then the hook is not catching the top thread. I assume your able to bring bottom thread to top?

Bring bottom thread to top, place sample fabric under pesser foot, lower foot, then hold both top and bottom threads in left hand and manually turn handwheel with right hand and see if will stitch.

Dropped stitch(s) implies the top thread is not being wrapped around the bobbin. The rotary hook must catch the top thread as the needle rises, pull additional thread into and around the bobbin and release the top thread. Then the takeup arm pulls the extra top thread from underneath the bobbin and sets the stitch to the selected tension.

If with no fabric it brings bottom thread to top then it's not likely a timing issue but rather an interference or tension problem. Test top thread tension... foot up is no tension, foot down is selected tension and should be noticeable by simply pulling on the top thread and note the difference between foot up vs foot down.

Comment below for further assistance.

Pull at least 6" of thread through the needle's eye and gently holding both thread tails gently when beginning to sew. Might try installing a brand new needle--make sure it is installed correctly. Raise the presser foot BEFORE threading the upper thread.

Pull bobbin thread to the top of the fabric before taking the first stitch.
How and Why to Bring up the Bobbin Thread

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Martha StewartSep 26, 2014 - We consulted Becky Hanson of Singer Sewing Company for her tips on ... The Problem: Stitches are coming out uneven or skipping entirely.

Basic Sewing Machine Troubleshooting - Sewing School

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Mar 16, 2011 - The thread breaks, my needle bends, or skipped stitches - UGH! Don't get ... Problem: My stitches are uneven and sometimes skipping!

My stitches are coming out uneven - SewingSupport.com

www.sewingsupport.com/sewing.../sewingsupport.../sewing.../my-stitches...

What to do if the stitches from your sewing machine are coming out uneven. Sewingmachine troubleshooting guide.

I'm sure you've done this, but I'll just throw this out there. Did you pull the bobbin thread through the groove that slants on the left side of the needle plate starting from the upper left corner of the bobbin cover?

Do you chose the right spool and put it the right side up?

Hai, Please check the bobbin tension and winding. And cleaning the machine.

try changing the needle or is the needle in correctly
check to see if the thread has come off the thread take up lever

If threaded correctly and it will not serge, you have probably just found out why it was in the garage sale. Take it to a qualified repair shop, mmost give free estimates, probably much more than you paid for it.

needle in backwards?

Sometimes when I need to use heavy thread for top stitching to reinforce a seam that has come undone, I will use the heavy thread on the top and regular thread on the bottom. I haven't tried it the other way around for hemming but I would think it would work. I do not currently have a Bernina.