I would take a look at the switch . A 250 is becoming an old motor now . It was one of the first jobs i did on my 230 , it would go down , but not up . I got it working intermittently by mucking around with the switch , until i got cheesed off with it and replaced the thing . Be warned they're expensive ! . Try manipulating the switch slowly , if you're stuck . No guarantees though .
Thanks guyz found the problem took out LH switch dismantled it looked perfect so decided to remove RH switch dismantled it and found burning on the circuit board where contacts are made cleaned it all off reassembled switch unit and now works perfectly. Hope this might be of help to others.