James, it will be the main module in the back of machine. We stock it at £56.28 + £6 post. If it does not sort the problem out, you can return it within 14 days for a refund, less our handling of £12. To order, go to our site at www.emwelec.co.uk and put WMD940 in the search box or call us tomorrow on 01159652118. Tony EMW Electronics
Tony
November 2014