microwave/oven combo

the microwave stopped working, pad would not respond. however, the oven still functioned. a repairman replaced the door switches and it still did not function. he then stated that the 20 amp fuse needed replacing and he did not have one with him. he reinstalled the unit and the oven also will not work. the display pad does not function or respond. it displays F2 (in red) followed by Ed ( in green). he tells me the key pad " just went out" he did not touch it or work on it. he adds that the keypad also needs replacement and the total will be $600.00. does this sound right to you? the serial # of the unit is; xf 3401054. help