Is the outlet connected to a waste via a jubilee clip around the pipe or to an 'upstand'? (Like a washing machine outlet - with a trap on the bottom of a short bit of pipe.
Any outlet blockage is likely to be in the area of that connection. Unscrew it and clean. Have a baking tray handy to catch any stuff from the drain on the d/washer.
You can always test the dishwasher part of the drain by hooking the pipe into the sink - if that works...get dismantling the 40mm waste plumbing!
As for it being built in - pull off the kickboard of your kitchen units - they clip on usually. There are perhaps two screws fixing the DW in place to the underside of the worktop. Remove. Lower the front feet - these usually have slots in so that you can easily do this...
There may be a slightly off-centre screw in the carcass of the machine - it should have an arrow pointing up and one pointing down! Turn the screw in the down direction to lower the rear of the machine. Make sure you don't kink any hoses when returning to its nest after you have troubleshot your domestic god
otess!
