The LEDs of your H8 grip shift controller (or ARC) lose visibility or stop working altogether. This article will explain how to diagnose and fix it.

Problem diagnosis

When with an Automatic or Harmony, you notice that the ARC grip shift display is always dark or only partially lit.

Perform a diagnosis by connecting the display to a working automatic hub interface:

Situation 1 - The problem is resolved, therefore the fault is in the hub interface.
Situation 2 - The problem persists, therefore the fault is in the controller.

Solution

If the problem is solved when connecting a working automatic hub interface:

Replace the automatic hub interface with a new one. Follow this guide for detailed instructions: How to assemble legacy Automatic or Harmony hub interfaces on a rear wheel and bike frame

If the problem persists when connecting a working automatic hub interface:

Replace the controller. Follow this guide for detailed instructions: How to assemble the legacy NuVinci H8 (ARC/grip shift) controller

If you are still facing issues it might be necessary to follow the steps for retrofitting or contact our service team.

If you follow the above steps, you should be ready to ride again. If you have any questions, don't hesitate to reach out to our Support team.