Our hotels have the G.E dishwasher model GSD2100N100BB. It at first did not drain, NOR did it spray. It filled. I took it apart a bit and I got it to spray,sling just fine. Now, read what I have done. It does have power to all things. It does go through the cycles right. it does open and close the solenoid, It does not have any clogs in the line to the sink. I took out the motor and the pump. I took off the chopper and that plastic round screen under the chopper. I cleaned the impeller. I blew through hose shaped like this [ . I looked at th flapper valve, and opened and closed it manually with the solenoid arm. I don't have a filter screen that goes acrosss the back of tub. I was in the sump,and it was clean. I do not see a piston/nut anywhere but I did feel a rubber thing I call a diaphragm because it is similar to that in a Fluidmaster toilet valve on the top of a Fluidmaster. I think that was inside the collection chamer port that goes to the hose shaped like [ . I don't know why that part is called a chamber coil, though. I don't see anything I would calll a coil. I do not see any parts in the colection chamer or the 'chaber coil" digram that looks like a that diaphragm piece. In the drain cycle I hear the otor run but the water does no drian out. I do not see anything I would call a "fine filter". I do think the water is going back into the tub when itg is supposed to drain. I have the plastic white ball, the check ball, or ball check. I tried putting it in the left and the right sides of the chamber body. Where does it go? Which way does my water flow in each cycle? I have one pump/motor, not two. I do not have an upper sprayer arm. Please don't tell me to check something i already did, because I have spent eight hours on this already, and none of the past threads on here are anything I havent checkked, or else they have parts my model does not have. I'm thinking it is maybe that rubber diphragm pice I mentioned, or the white ball in the wrong spot, since i don't know which direction the water flows in each cycle. Does anyone know this exact model? Piston and nut? is that the diaphragm thing? What nut? Thanks.