Took of side panel (LHS) where all manifolds, valves and pipework can be found. Immediately obvious that several areas clogged (dirty black deposits and 'sludge'). Spent a couple of hrs carefully disassembling and cleaning. All dishwasher cleaning functions now restored - this situation...
Top tray not washing. Upper spary arm clean and water seems to drain away ok. Filters clean and no obvious blockages in internal ducting. Water does pool in lower filter cylinder - but this may be normal or is all water evacuated. Do I need a plumber to state the obvious or is their a fix?