Push Button Flush Toilet is not working - why?????

When the button is pressed on my toilet cistern I can hear the air being pushed through but nothing happens. I guess it's something to do with the internal fittings - probably seized with lime scale etc. but I have no idea how these new cisterns work - are there any diagrams / instructions for me to follow so I can get it sorted without having to wait for ages for a plumber to call?????
Any help advice / appreciated... Thanks