Your breadmaker no doubt plugs into a standard household power socket - the digital display will be powered from a low voltage source - the low, DC voltage being made somewhere inside the breadmaker. Either the DC supply for the digital display is defective or the display itself is broken.
You will need small hand tools to dismantle the machine and a test meter for an initial diagnosis - a schematic might help but probably not much.
It may be possible to repair your breadmaker but I doubt very much that it will be easy - I suspect you will be better placed with a new one. Repair time, effort and the cost of spare parts do not make fault finding worthwhile on small appliances.
Good luck...
Peccavi
October 2009