Watch your connector carefully. There is a slider lock (C shaped) sticking from left side. Once you take the pump out, you can separate the cover from the sole, and you will see the pump. If your pump unit is making sound after lock/unlock operation, then motor is working. For such case, you should further disassemble pump unit by releasing two screws on the bottom. You will most probably see a broken coupler between propeller and motor shaft. Now, you should be creative enough to fix the coupler. It is not sold by MB. I made it by metal wire of 1.5mm diameter and working perfectly. Don't abondon your money. If you need my help, give me a mail.