The Input/Output light comes on, but I have cleaned the input filter and output as described in the manual.
If I mop out all the water from the pump and output area, it runs for just one cycle. Next time I run it, it gets as far as starting the water input, but then it cuts out again and the Input/Output warning light shows. It doesn't even get as far as opening the soap dispenser. It doesn't seem to be leaking anywhere.

Ed, October 2013