Nucleus A not connecting via Ethernet after power outage (ref#RHAXVP)

Support
1

Is Roon Server running?

· No, Roon Server is not running.

For Roon connectivity to work properly, both Roon Server and Roon Remote need to be turned on.

· Roon Server is on, but I'm still having trouble connecting.

What do you see on your screen?

· "Waiting for your Roon Server"

What happens if you press the "Select a different Roon Server" button?

· I don't see Roon Server.

Please try to restart your network setup by unplugging, waiting 30 seconds and then replugging in your networking gear.

· No, the issue remains the same

Please select how you've connected your Roon Server to the internet

· Roon Server is connected by *Ethernet*

Have you checked your firewall settings to ensure that Roon is allowed through?

· Roon still won't connect even after checking this aspect

Have you verified that Roon Server is on the same subnet as your Remotes?

· My Remotes and Server are on the same subnet and I still can't connect

Sometimes the issues can be resolved with a reinstall of your Roon Remote app. Let's try to perform a reinstall and see if it helps.

· I've reinstalled the Roon Remote but it did not help

What is the operating system of your Roon Server host machine?

· *Nucleus*

Select any of the following components that are present in your local network setup

· None of the above

Describe the issue

My Nucleus A will not connect via ethernet following a power outage. There is a flashing green light and a red light on the ethernet port on the Nucleus. The Roon server is not showing up in my network or my Mac. The Roon software is searching but cannot fine Roon Server.

Describe your network setup

Via ethernet to BT/EE router. It has been working well, but the power outtage has stopped it working

2

I have now made it worse by mistakenly clicking the set up on this mac button so now I can’t get in anyway. The ethernet port on the Nucleus is red.

3

Also, I do not have a monitor, just the iMac

4

Hi again, I really could do with asisstance on this please…I cannot get my Nucleus to work at all.

5

Hi @Julie_Meikle,

For the Mac, (now running Roon server) go to Roon settings in the Roon GUI and disconnect from Roon. This will allow it to search for any active Roon Servers once more.

An alternative to a monitor is a TV with HDMi input.

Seeing what is / what is not displayed will really help to determine next steps and how best Roon support staff can help you.

Roon support will follow up on this once it reached top of there queue.

6

Hi @Julie_Meikle,

Thanks for the update — we understand how frustrating this is.

At this stage, connecting the Nucleus to a monitor or TV via HDMI is a critical part of troubleshooting. This step allows us to determine whether the unit is:

  • Successfully booting into Roon OS
  • Detecting the network interface correctly
  • Reporting any hardware or network-related errors on startup

Without the HDMI output, it’s not possible to reliably distinguish between a network issue, a corrupted startup state after the power outage, or a potential hardware fault. Skipping this step can lead to unnecessary back-and-forth or even shipping the unit when it may not be required.

If you don’t have a computer monitor available, any TV with an HDMI input will work.

Once you’re able to connect via HDMI and see what’s displayed on screen, please let us know exactly what you see — that will allow us to advise on the correct next steps as efficiently as possible.

Thank you for your patience while we work through this with you.

7

HI Thank you. I have connected to a TV and all I get is a blank screen. Initially I got a ‘no signal’ message but disconnected the Nucleus and it went to HDMI on the TV and the blank screen.

Thanks
Julie

8

OK I Managed to connect. I drained all residual power by disconnecting then holding down power button etc. on reconnecting the message attached popped up then disappeared.

IMG_3111
IMG_31114096×3072 309 KB

Saying: warning: e

tollowing warnings tat were detected during this boot.

ese can be viewed in setup on the fuent Log Page.

RNING : CMOS Battery Failure

RNING : CMOS Checksum Error

RNING: CMOS Time Not Set

9

Hi @Julie_Meikle,

Thanks for all of the additional information! It is clear you’re unfortunately suffering from a hardware-related failure on the Nucleus. The CMOS battery to be specific. The best next steps here would be to get in touch with our Nucleus RMA team to send the unit in for repair.

To do so, open the Typeform link below and select ‘Other’ followed by 'This issue is related to a physical component".

Typeform link : Nucleus Troubleshooting

Screenshot for reference:

Screenshot 2024-08-30 at 10.55.51
Screenshot 2024-08-30 at 10.55.51836×394 32.6 KB

They’ll help get you sorted out moving forward. Thanks! :+1:

10

Thank you. I’ll do that, but question costs involved :slightly_frowning_face:

11

Hello @Julie_Meikle,

Thank you for the update.

If you’re comfortable doing so, you can replace the CMOS battery yourself, or alternatively bring the unit to a local PC repair shop to have it replaced.

The Nucleus uses a CR2032 CMOS battery with a connector (not a loose coin cell). A compatible replacement can be sourced easily from online retailers or computer repair shops.

For reference, here is a disassembly guide for the Nucleus One. While it’s a different model, the internal layout and battery replacement process are very similar:

If you’d prefer not to handle this yourself, please let us know, and we can discuss sending the unit in for service via the RMA request that you have already opened instead

12

Thank you. I have now done this and the error/warning messages have gone. I still cannot see the Nucleus on the network.

So far:
I connected to my macbook (connected to the same network as all my other Roon apps/desktop Mac and it found the Nucleus straight away …it was the server when I last used the macbook. It worked, but only on the macbook. I still cannot see it on the network and I still have the mac as the server on the other remotes/mac.
I made the mac the server by mistake on the Desktop Mac when I could not access the Nucleus.

The Nucleus is working, finding music and accessing Qobuz playlists on the macbook, but not anywhere else. It is now allowing me to connect to the Nucleus but says I need authorisation. I want to use the Nucleus not the Desktop Mac.
Please help as I am at my wit’s end!
Julie

13

Hello,

Thank you for the clarification — this helps.

At the moment, your other devices are still connected to the MacBook as the Roon Server. To switch everything back to the Nucleus, you’ll need to log out on each Remote individually.

Step 1: Log out on each Remote (one by one)

On each device where Roon is installed (Desktop Mac, iPhone, iPad, etc.):

  1. Open Roon
  2. Go to Settings → General
  3. Select Log out

This action only affects the current device and does not log out other Remotes automatically.

Step 2: Select the Nucleus as the Server

After logging out on a device:

  1. Relaunch Roon on that same device
  2. When prompted to Select a Roon Server, choose Nucleus
  3. Sign in with your Roon account credentials to authorize it

Repeat this on each Remote as needed.

Once the Nucleus is authorized, all Remotes should connect to it normally instead of the MacBook.

Please let us know once you’ve completed these steps or if anything is still unclear.

14

Thanks. That has worked for all of the remotes apart from the Roon app on the desktop Mac. It is still only offering the Mac server.
When I 'find OS" It just hunts and hunts and does not find. I still cannot access the internal SSD on which I have ripped CDs.
Thanks
Julie

15

Ah! I think all the remotes are connected to the Mac server. They are named Nucleus for some reason. When I restarted the mac the music stopped…I tried this with all the remotes and zones. So the Nucleus is still not being seen at all.
Julie

1 Like
16

Also the router is not showing connection to the nucleus only the mac

17

IMG_0336
IMG_03362732×2048 489 KB

18

Hello @Julie_Meikle,

Thank you for the update.

Could you please confirm whether you do not see any of the following information on the screen when the Nucleus is connected to a monitor or TV via HDMI?

HDMI Diagnostics
HDMI Diagnostics1920×843 96.8 KB

If the screen remains completely black, as you mentioned, this may indicate an OS-level issue, potentially caused by the recent power outage.

In this case, there are two available options:

  1. Reinstall the operating system using the official recovery guides
    https://help.roonlabs.com/portal/en/kb/articles/rock-install-guide
    https://help.roonlabs.com/portal/en/kb/articles/roonos-recovery
    , or
  2. Proceed with the existing RMA request and send the unit to us for inspection.

Please let us know which option you would like to proceed with.

19

Thanks. The screen is blank. Do you have an idea about costs if I send the unit back via the RMA process. I am in Britain.

If I try the recovery I will need a TV/monitor, a keyboard and mouse and USB drive, is that correct?

20

Hello @Julie_Meikle ,

Yes, you will need a keyboard, TV/Monitor and a USB drive to try the recovery.

Since you are located outside the US, any repair would have to be done through our local distributor. You can message the RMA team using @benjamin ‘s instructions from above, and the RMA team can put you in touch with our distributor to learn about the repair cost for your territory.