Troubleshooting
136 Service Instructions 867 - 04.0 - 10/2019
Skip stitches Needle thread and hook 
thread have not been 
threaded correctly
Check threading path
Needle is blunt or bent Replace needle
Needle is not inserted 
correctly into the needle 
bar
Insert the needle correctly into 
the needle bar
The needle thickness used 
is unsuitable
Use recommended needle 
thickness
The reel stand is 
assembled incorrectly
Check the assembly of the reel 
stand
Thread tensions are too 
tight
Check thread tensions
Throat plate, hook or 
spread have been 
damaged by the needle
Have parts reworked by qualified 
specialists
Loose stitches Thread tensions are not 
adjusted to the sewing 
material, the sewing 
material thickness or the 
thread used
Check thread tensions
Needle thread and hook 
thread have not been 
threaded correctly
Check threading path
Needle breakage Needle thickness is 
unsuitable for the sewing 
material or the thread
Use recommended needle 
thickness
Error Possible causes Remedial action