Hotpoint Dishwasher DWF31?

1. switch on and drain pump works as should. The inlet opens and water enters the machine but it seems that there is no pump working to draw the water in to the main chamber. appears that the water enters from initial pressure /gravity. It is observed at this time that as the water enters it fills up the float chambers thus swiching the barometric microswitch and also lifts the float in the second chamber and activating the drain pump. This causes most of the water that has entered the main chamber to be drained. Subsiquently there is not enough water in the machine to let it perform its cycle and thus stays on '2HR' timer.
I have manually put water into the main chamber and set the machine running. this worked until the water was drained during the cycle and then the initial problem kicked in.

Is there a pump/impellor that might be U/S or blocked. If so how do I get to it?

Any thoughts would be appreciated.