Servis M6135 washing machine wont spin?

Hi there,

Please can you help? My Servis M6135 will not spin at the end of a cycle. After a rinse, the pump operates and empties the drum, but continues to pump for ages even when all the water has gone. Eventually the machine gives up and indicates the cycle has finished. I've tried the pump/spin setting and the rinse setting too, with the same results. The motor appears to run ok when asked to tumble, and turns over gently even while still trying to pump out water that isn't there. I've poured water into the drum and this drains away fine under gravity. I've removed the pressure switch connected by the long thin pipe to the bottom of the drum and tested it. There's continuity between each of the 2 red wires and the black one when i blow onto the pipe connection. I presume this is working fine. The wires on the control module and the rest of the machine seem secure. Now i'm stuck!