My husband recently purchased a Janome and is already having problems. When sewing the thread bunches under the fabric as though the tension is too loose. It even causes the top thread to break.
We've checked and replaced the: bobbin, bobbin thread, needle, top thread and test fabric. The needle is centered and doesn't hit the plate. The tension has been tightened and loosened and it's been rethreaded several times. He's pulled out the bobbin casing, cleaned out what little lint there was as well as removed the plate and inspected the interior. All to no availe. The darn thing doesn't want to work and it's not even 2 months old.
Any other suggestiongs or does he take this thing in for repairs?
Sewing is an artform not a hobby!
You don't mention which model you have, but the bunching of thread suggests you are not getting the top thread seated in the take up arm correctly. When you thread up the machine, apply a little tension to the reel end of the thread, make sure the thread actually enters the eye of the take up arm, if it doesn't, you end up with excess thread under the throat plate wrapped around the bobbin area and creating an awful mess.
What happens if you don't get the thread into the guide channel of the take up arm is the thread slides down the back of the take up hook, that prevents the arm and the take up spring from pulling back the extra thread needed to pass around the bobbin race when capturing the bobbin thread. If you raise the take up arm to its highest point and look down to where the eye is, you should see if the thread is seated in it. You can open the end of the machine which will show you clearly if the thread is properly seated in the take up arm, or has as I suspect only draped over it. It's very easy to miss that guide channel, as everything is designed to be hidden from view giving a nice uncluttered look to the body of the machine.
Also make sure the presser foot is raised when threading, that opens the thread tension plates, then when you lower the foot the thread is forced through the plates. Leave the foot down and you risk by passing the tension mechanism.