I had the same problem, try cleaning up the edge contact strips on the top r/h side of the circuit board which contains the led's and programme dials.
Also, clean up as best as possible the edge connector plug (there is only one which fits onto this board) which fits onto the aforementioned edge contact strips. It worked for me as I found dirty copper contacts gave an intermittant lit led when i tweaked the little red wires leading to it. I gently rubbed the copper with the wifes emery nailboard and cleaned the dust off with acetone (good for cleaning copper tracks) available from chemists over the counter.
Rob, February 2010