Troubleshooting your Kenmore overlock sewing machine when its needle won't move
A disengaged clutch, broken drive belt or internal drive gear failure can prevent the needle from moving.
Engage the hand wheel clutch if you have it disengaged for bobbin winding. If the needle won't move with the clutch engaged, unplug the sewing machine and check the drive belt. Replace the drive belt if it's broken.
If the drive belt is okay, an internal drive gear failure is likely preventing the needle from moving. You'll typically need to have a service technician examine the sewing machine and fix a drive gear failure.
What to do when your Kenmore overlock sewing machine won't turn on
A power supply failure, bad outlet cord or a failed On/Off switch can prevent the sewing machine from powering up.
Check the power supply first. Plug a lamp or other small appliance into the electrical outlet that you're using for the sewing machine to make sure the outlet works. If the electrical outlet is dead, reset the house circuit breaker for the outlet. If the outlet still doesn't work, try using a different outlet to power the sewing machine.
If the electrical outlet is okay, unplug the sewing machine and check the outlet cord for damage. Replace the cord if it's damaged.
If the outlet cord is okay, check the On/Off switch for continuity using a multimeter (with the sewing machine still unplugged). With the switch turned to the 'on' position, the meter should measure near 0 ohms of resistance through the On/Off switch. If the meter measures infinite resistance, replace the On/Off switch because it's preventing the sewing machine from getting power.
Error Codes
Owner’s manual