Troubleshooting
Operating Instructions 669 - 00.0 - 08/2019 111
Missing 
stitches
Needle thread and hook 
thread have not been 
threaded correctly
Check threading path
Needle is blunt or bent Replace the 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 installed 
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