How to Fix Bosch SRS43A02GB classixx dishwasher?

The basic problem is that the machine will not empty.
The part or model number = SRS43A02GB/08 Type = SD13H1B
The following link seems to apply to my machine which appears to be manufactured around 2002. User Manual 5600 046 517(8203) applies.Thanks to those who already gave advice!
http://www.diynot.com/forums/viewtopic.php?t=181603
The picture shown shows the same type of matrix.
I have cleaned all filters & the sump appears to be clear.
The pump is running OK but there is no head of water at the matrix yet the machine will empty statically if the outlet is removed at the matrix.
It seems as though there is a blockage or valve closed between the pump & matrix. If you try to back blow the pipe into the sump it appears blocked.
Is it possible for the impeller to be damaged such that it will not pump - I can see the head of the impeller but can't feel any vanes.
Any suggestions welcome!!

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