We may have found other answers which could help you.
Click here for Issue Sewing Threadhow can i fix my Lervia KH400 sowing machine?
It won't pick the bottom thread up?
Sewing machine issue?
Lervia KH 4000?
Lervia Free Arm sewing machine KH4000 ?
How do I unjam my Lervia KH4000 Sewing Machine?