If when you press the on/off button no light is comming on then you have a power supply fault.
The first thing to do is check the plug socket. If the socket is hiden behind a unit have a look on the wall around the kicthen and see if theres a switch on the wall that isolates the dishwasher. Turn them all on and see if the dishwasher comes on then.
If you cannot see an isolation switch then you need to access the dishwasher plug and try it in an extension lead from a socket that you know works.
Check that out first and see what you find and let me know as i can then advise further from there once we know the power supply is fine.
When you press the on/off switch on the left then its the lights on the right that should come on no matter what program you have set. As when you press the on/off button all the lights light up for a few seconds then just the single program light should stay lit.
So still check the above sockets and switchs and see what you find.