Unfortunately, on the WF640 holding start rarely pulls it out of test. This is a classic main module fault (it is in the back of the machine in a white plastic box). Change the module and it will be fine. We stock them at £65.88 inc post (exchange). Our modules are ready programmed for your machine. go to our site at www.emwelec.co.uk and put WF640 in the search box. You can order online or call us on 0115 9652118 Monday
www.emwelec.co.uk, January 2012