Do you hear the pump when you turn on the brew switch?
If not, you have an electrical problem like faulty switch.
What happens when you switch on the middle switch -- the hot water only one? Does water emerge from the steam wand? If yes, pump is ok.
Hate to state the obvious, but is there enough water in the container?
Does water come out from shower screen without the portafilter? If yes, you could have a blocked portafilter.