If the display function does not work, replace the meter unit.

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)DFI Power Source
ECU Fuse Removal
Refer to the 30 A Main/15 A ECU Fuse Removal in the
Electrical System chapter.
ECU Fuse Installation
If a fuse fails during operation, inspect the DFI system to
determine the cause, and then replace it with a new fuse
of proper amperage.
Refer to the Fuse Installation in ...
Before Servicing
Before starting to perform an inspection service or carry out a disassembly
and reassembly operation
on a motorcycle, read the precautions given below. To facilitate actual
operations, notes, illustrations,
photographs, cautions, and detailed descriptions have been included in each
chapter w ...
Lights and Switches Operation Inspection
First Step
Set the gear position in the neutral position.
Turn the ignition switch to ON.
The following lights should go on according to below table.
If the following light does not go on, inspect the meter
unit (see Meter Unit Inspection in the Electrical System
chapter).
...