Troubleshooting

Fault	Possible Cause	Troubleshooting
Skipped stitches	Incorrect needle/thread combination.	Use a needle with a suitable needle size. Selecting the needle
	Threading is incorrect.	Rethread the needle and the looper thread paths. Threading
	The needle is defective.	Replace the needle. Changing the Needle
	The needle is incorrectly inserted.	Insert the needle correctly. Changing the Needle
Irregular stitch	Thread is not correctly inserted in the thread pre-tension.	Check the thread path. Threading
	The thread tension is incorrect.	Adjust the thread tension. Thread Tension
	Incorrect needle/thread combination.	Use a needle with a suitable needle size. Needle
	Thread threading is incorrect.	Rethread the needle and the looper thread paths. Threading
	The fabric has been pulled.	Feed the fabric evenly.
	The presser foot is loose.	Attach the presser foot. Removing the Presser Foot Sole
	The air threader pipe is blocked.	Clean Air Threader Pipes. Clean Air Threader Pipes
Needle breaks	The needle is defective.	Replace the needle. Changing the Needle
	The fabric has been pulled.	Feed the fabric evenly.
	Incorrect needle/thread combination.	Use a needle with a suitable needle size. Selecting the needle
	The needle seat is incorrect.	Tighten the needle screw. Replace the needle. Changing the Needle
	The presser foot is loose.	Attach the presser foot. Removing the Presser Foot Sole
	Incorrect needle.	Use needles from the needle system ELx705 CF. Selecting the needle
Unwanted seam puckering	The thread tension is incorrect.	Adjust the thread tension. Thread Tension
	Defective needle.	Replace the needle. Changing the Needle
	The setting of the Differential Feed is not optimal.	Set the Differential Feed to 0.7 − 1. Adjusting the Differential Feed
Unwanted weavy seam	The setting of the Differential Feed is not optimal.	Set the Differential Feed to 1 − 2. Adjusting the Differential Feed
Thread breakage	Incorrectly threaded.	Rethread the needle and the looper thread paths. Threading
	The needle is blunt or bent.	Replace the needle. Changing the Needle
	The thread tension is not optimal.	Adjust the thread tension. Threading
	The thread is tangled.	Check thread feed from the thread spool. Spool Holder
	Thread guide is not fully extended.	Pull out the thread guide completely. Retractable Thread Guide
Machine does not sew	The looper area is open.	Close the looper cover properly. Looper Cover
	The machine is not connected to the power supply.	Insert the mains plug into the socket and into the machine. Connecting the machine Check the socket for power.
	The machine is switched off.	Switch the machine on. Connecting the machine
	The machine is overheated.	Switch off the machine and leave to cool for 10 − 15 minutes. Connecting the machine
	The machine is too cold.	Leave the machine at room temperature for approx. 1 hour.
Machine runs slowly and then stops	The pulse drive is performed.	The machine prepares the threading position.
Fabric is not feeding properly	The stitch setting is not optimal.	Elongate the stitch length. Setting the Stitch Length Adjust the Differential Feed. Adjusting the Differential Feed
Fabric is not feeding properly	The presser foot pressure is not optimal.	Adjust the presser foot pressure. Setting the Presser Foot Pressure
Fabric jam	The presser foot pressure too high.	Reduce the presser foot pressure. Setting the presser foot pressure
Looper thread cannot be threaded	Air threading pipe is not closed properly.	Turn the air threader switch completely to position I. Threading the Looper Thread / Adjusting the Differential Feed Check the connection of the air threader pipe.
	Threads with special properties (e.g., bulky yarn or metallic yarns).	Pull in the thread using a thread cradle.
	The air threader doesn't work.	In case of a malfunction or damage, repair by an BERNINA dealer is necessary.
Looper cover does not attach	The air threader switch prevents attaching the looper cover.	Turn the air threader switch completely to position 0. Threading the Looper Thread