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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Meter Unit Removal/Installation
Remove the upper fairing assembly (see Upper Fairing
Assembly Removal in the Frame chapter)
Remove the bolt [A] (other than US, CA and CALmodels).
Slide back the dust cover and disconnect the meter unit
connector [B].
Remove:
Bolts [A]
Nut [B] (other than US, CA and CAL mode ...
Lower Fairing Installation
Installation is the reverse of removal. Note the following.
When installing the pad [A], align the edge of the pad and
the marking of the fairing [B].
When installing the pad [C], align the edge of the pad and
the fairing [D], and fit the edge of the pad to the boss [E].
Insert the hoo ...
Idle Speed Control Valve Actuator Installation
Replace the O-ring [A] with a new one.
Apply engine oil to the new O-ring.
Install the idle speed control valve [A] as shown in the
figure.
10° [B]
Tighten:
Torque - Idle Speed Control Valve Actuator Retainer
Screws: 2.06 N·m (0.21 kgf·m, 18 in·lb)
Install th ...