If the light on the power button comes on and there is no LED display then it will need either a new control panel for around £60 (which just plugs in) or more likely a new PCB which will cost you around £200 (again you could easily fit it yourself).
I had the same and replaced both as per ideal....mine still doesn't work though and it's the 3rd time it has broken down in 2.5yrs....I now have a flashing L and F error message!
Good luck!
Dave
December 2005