DIAGNOSIS No power is reaching the control board. This is usually a failed thermal fuse or a loose internal connection, not the display itself.
FIX First, check your outlet with another device. Then, check the power cord where it enters the fryer base for damage. Unplug, wait 10 minutes, then plug it back in firmly. Sometimes a power surge can trip an internal safety.
IF THAT DIDN'T WORK The internal thermal fuse, located near the heating element, has likely blown. This is a safety device. It requires disassembly and soldering to replace. This is a job for a technician.
HEADS UP Do not attempt to bypass any fuses. This unit has overheated and the fuse did its job. A repair must address the cause of the overheating.