If your sewing machine show's the E1 Error, then you have to open your sewing machine and replace the fuse.(you have to open the right Cover on Front where the Display is placed, because there is the circuit board placed!)
There are 3 Fuses in the Sewing machine and they are placed at the printed circuit board. It should be the Fuse in the middle. (not those with the wire in it!)
It's not easy at all to open the machine, the best thing you can do (if you have a Digicam) take some Pictures of the wiring so it will be much easier to put it back together.
I'm NOT an Expert; but a passionate hobbyist. ;)
If you are too; just save yourself further trouble with the helpdesk, and fix it yourself.
I hope this post could help you!