I had the same problem today. The good news is I fixed it without replacing any parts. I tried a few things which may have worked so I will list them all. I'm not sure which one worked so try the easy ones first.
Fill the salt and rinse aid depensers up.
Once it starts beeping continously close the door and let it drain itself. Do this several times. Turn it off and leave it for a minute between goes.
With the power button light on leave the door open slightly for about 15minutes, mine beeped after about 7 minutes and it had reset itself.
At the bottom of the dishwasher underneath there is an anti flood switch. My tray had water in it and caused the float to rise up and activate the switch which stops it from working. Easiest way to drain it is to pull the dishwasher out put down a load of towels and tip it backwards until all the water is gone. I found it easier to check for water through the right handside side panel, it comes off pretty handy.
I also removed the upper front cover to check the door catch switch. Just make sure its not broken and not wore down etc. I also sprayed it lightly with WD40.
Try disconnecting the wated inlet pipe at the back once you have turned the water off. Mine had a lot of pressure in it which it should probably should have but read somewhere else it solved their issue.
I then stripped both sides off laid the machine on its back, make sure to disconnect the water inlet pipe and took apart the drain pump. If your looking at the back its on the right hand side, mine was dark grey and was attached by two screws to the side panel. There is 4 or 5 screws which hold the drain pump together. Unscrew these and again there will be a build up of pressure and water released. There might be a foreign object stuck in here which will stop the blades turning. Check the espares youtube channel on how to remove this, thats what I did.
After all this mine didnt work straight away and I had given up. But I left the power on with the door open slightly and after 7 minutes it beeped and I was able to select a program as normal.
Maybe the turning over on its back and release did the trick Im not sure but give it a go. Good luck
Rob, July 2014