Dishwasher won't fill with water?

My Bosch dishwasher (est.10yrs old) appears to correctly go thro' the rest of the cycle but it will not fill with water, and stops whenever fresh water would have been filling.

I even washed by adding water when required through the front door!

So what do you think? Is it the solenoid (?)that acts as a valve to the incoming water, and how are they tested if you think that is my first port of call?

THANKS!