Hotpoint washer/dryer wd62 failed to start up. Bought a new door interlock switch (zv-445) and fitted. Closed door and turned on and the washer started - the solenoid water valve opened and neon light turned on. Because I had not replaced the machine back plate I turned off the washer. Since then it has refused to start again and all the three terminals of the interlock switch give 240 volts whether the door is closed or not. The pcb is powered and no visible faults. What has happed? Any help or suggestions much valued.