A Husqvarna Viking is a quality sewing machine that will provide years of trouble-free performance if attended to properly. Whenever you are having problems with skipped stitches, bad tension or funny noises, there are a few basic troubleshooting points to check before having your machine serviced.
Re-thread the machine, making sure to do it correctly. Thread that is out of place will cause skipped stitches, poor tension and the "bird's nest" of tangled threads on the wrong side of the fabric.
Check the take-up lever while re-threading. Husqvarna Viking sewing machines have a jam-free bobbin, so most stitching problems are actually caused by the upper thread being threaded incorrectly. Thread that has come out of the take-up lever usually escapes the sewer's notice, but causes many stitching issues.
Take out and replace the bobbin, making sure to do it correctly. Most Husqvarna Viking bobbins have an "H" logo/symbol on the top which should be facing up or out, depending on your model. Make sure the thread is going through the bobbin tension correctly.
Clean the machine. Remove lint, thread or other debris from the bobbin area, feed teeth and tension discs using a small lint brush or paint brush or vacuum with mini attachments. Dust in the bobbin area and tension discs can cause uneven tension. Since a Husqvarna Viking does not require oil, proper cleaning is essential.
Replace the needle with a new, sharp one. Bent and dull needles will cause skipped stitches, clicking noises and cause runs in fabric.
Change the needle to one that is appropriately sized and suitable for your project. Thicker fabrics require heavier duty needles and stretch fabrics require stretch or ballpoint needles.
Check that the tension is set appropriately. Most Husqvarna Vikings have the mid-range tension marked on the tension dial.
Check that the foot pressure is set appropriately. Most Husqvarna Viking sewing machines have a dial to control the pressure of the presser foot on the fabric. Fabric that is not feeding properly may be caused by a lack of pressure from the presser foot. Consult your user manual for the location and proper setting of the foot pressure dial.
Make sure the machine is plugged in properly.
Make sure the foot pedal is plugged in properly and nothing is obscuring the depression of the foot pedal, or is inadvertently pressing down on the gas pedal. Sometimes a sewing machine that won't stop is the result of a foot pedal being pushed on by something other than the sewer's foot.