U2D2 can not Find DYNAMIXELs

Hello everyone, I currently have 2 U2D2 devices in my hands (one of which was recently purchased and has not exceeded 3 months). I am searching for a steering gear, as shown in the figure:

A phenomenon has occurred:

A U2D2 can search for the steering gear (normal),

Another one cannot be searched (abnormal)
The equipment I debugged is as follows:
12V 5A power adapter
U2D2+U2D2 Power Hub
Android data cables (all purchased in original packaging)
Known conditions: The same line and power supply equipment, the same steering gear, and the same settings (including baud rate) result in one being searchable and the other not.

Can it be the problem of communication chip damage? There have been no quality issues with U2D2 products before, and this time it’s strange. Let’s infer which part of the problem has occurred.

What is the model of the two DXLs that you are using? Have you made sure that they have separate IDs?

Only one connected。Using two different U2D2

In that case, try to set DXL Wizard to scan for all baud rates and do firmware recovery on the problem dxl

There is no problem with DXL itself. The current issue is that U2D2 cannot search. You may have misunderstood my meaning. It would be great if you could upload a video here, as the video may be clearer to watch

Sorry that I misunderstood your wording. You said “cannot be searched” instead of “cannot search” so I thought that you were referring to a DXL instead of a U2D2. If the problem is a U2D2 there is not much that an end user can do. Hopefully it is the new U2D2 unit so that you can do an RMA process with ROBOTIS. @Jonathon can help you.

As @roboteer said, there’s not much that you’ll be able to repair yourself inside a U2D2 unit.

If the unit that’s giving you these issues is new, there’s a possibility that it might be covered under warranty. If it’s an older unit though, it would probably cost you more to send it in for repairs than it would be to just purchase a replacement.

If you would like your hardware repaired by ROBOTIS, you can submit an RMA request to your region’s ROBOTIS retailer.

When submitting your items for RMA service please be advised: in the event that the units are not covered under warranty you will be responsible for the cost of shipping + repairs (labor/components) before ROBOTIS may return the RMA units.

To proceed with RMA service fill out the the appropriate form from the list above to open a request with your region’s RMA team. In addition, you may find the troubleshooting self-checklist useful to assist in filling out the RMA request form.

Okay, I understand that,thank you for your serious answer.