It won't stop!!! I have inherited an Elna Contessa and it was working fine the other day until

Question

I have inherited an Elna Contessa and it was working fine the other day until suddenly it sped up to full speed and wouldn't stop going! The needle is jumping up and down like a jackhammer and luckily I saved my garment from being ruined but I can't figure out how to make it stop! Can anyone help?!

Believe it or not, my Elna did the same thing yesterday. It is a Contessa 310, about 30 yrs old (mums) but in almost new condition as she never did get round to much sewing! Any luck getting a solution to your problem??