Have you checked the SATA cable on your internal storage, that it’s seated properly both ends?
Edit: ah, I see we’ve already been down that route. Then it may be that the SSD itself is failing?
There was this rather worrying story in Ars Technica recently:
Mine is a Samsung SSD 860 4tb and I believe many others on here use the same model . Im not sure being seen with full library , then missing , then full , then missing , then back but empty of library are signs of dying exactly . It’s probably just as likely a problem with Nucleus+ or software but no way to be sure .
M
Hey @Moonloop,
I wanted to check in to see if your nucleus was still crashing? After reviewing a more recent diagnostics on your account, I’m seeing a fair amount of network errors stemming from the Nucleus.
With that, I think resetting your network settings on the device may be helpful. Steps to follow below:
Connect the Nucleus to a monitor or TV via HDMI
Connect a USB keyboard to the Nucleus
Press ENTER
Type resetnetwork
Press ENTER
All network settings will now be reset and you can try connecting to the Core once more. Let me know how things run after this 
Hi Ben
This is what the home page looks like so I was actually thinking of turning it off for a bit as it’s depressing to look at ! I will follow your instructions after work .
Thx for your help
M
Hi
I managed to reboot and restore a previous backup and then connected to Nucleus + and
resetnetwork and , so far , system and Arc have been up for 1 day and 8 hours ! Is there anything else you need to look at that might explain why this is happening ?
M
Hey @Moonloop,
I’m glad to hear things are running smoothly! Because things are functioning properly on an older database/back up, you could have minor corruption on the current database you were using prior to the restore.
Have you run into this issue since performing the restore?
Hi Ben ,
Unfortunately , the wheels have come off again . I suspected trouble when I started trying RoonArc on the way to work to no avail . It’s getting depressing now Nucleus + and/or Library have become so unreliable I may have to go back to my old 2012 Mac mini or dig out JRiver and try my luck .
The latest pix show that the drive has disappeared again and library consequently vanished 
M
When you checked the SATA cable earlier, did you actually reseat it (i.e. unplugged both ends and then plugged it back in again), or just check that it was seated in the connectors?
The symptoms do seem to be indicative of an intermittent fault somewhere in the SATA channel, either in the cable, the connections, the SSD or the Nucleus’ motherboard.
One way to check whether the fault lies in the SSD or elsewhere would be to put the 2.5" SSD into an external USB drive housing and see whether the fault disappears or not. Something like this would be a cheap way to test the hypothesis:
Hi
Before I had a chance to try anything , I rebooted the unit and lo and behold drive is seen , library returns ! Is there a way to return the Nucleus+ to 'factory state ’ if I remove the SSD ? How can I keep it from formatting the drive if I wanted to put it back in ?
M
Nucleus+
Operating System
Reinstall
OK
Version 1.0 (build 254) production
Running 1 minute, 2 seconds.
Roon Labs Software
OK
Version 1.0 (build 14) production.
Running 0 minutes, 47 seconds.
Roon Server Software
RestartToggle Dropdown
OK
Version 2.0 (build 1211) production
Running 0 minutes, 44 seconds.
Roon Database & Settings
Reset
OK
88% of 55 GB available.
Internal Music Storage
Format
OK
4000GB, Samsung SSD 860 39% of 3696 GB available.
But haven’t we been here before? If it’s an intermittent problem, then there’s no guarantee that it will not come back.
Having formatted the drive once with the Nucleus administration page, you don’t need to format it again if you remove it and then put it back.
The way to return the Nucleus to “factory state” is to click Reset next to the Roon Database & Settings section on the web administration page. While this will not make any changes to your internal storage, I’m not sure why you would want to do this?
The thing is , I can no longer trust what I’m being told by the UI as you can see here
It reported the SSD as containing nothing with the full 4tb capacity ‘Not Ready’ without being formatted first . My thinking with a factory reset was to reinstall OS and any software that could have become corrupted . I still can’t be sure whether it’s Nucleus+ hardware/software , SSD failure or something else that’s causing it but it is definitely no longer a plug’n’play solution for me . When I leave home , I can’t be sure whether I will be able to listen in on RoonArc or not and that’s really not good enough .
M
This is simply proof that the intermittent fault is still present.
I understand from the Support team that your logs show errors in the SATA channel, which is what connects with your internal SSD.
The next step would be to try and isolate where it lies. That’s why I suggested that you put the SSD into an external USB housing. If the fault goes away, then the problem lies somewhere inside the Nucleus’ SATA channel (cable, connectors or motherboard), and if the fault is still present, then it is the SSD itself that is causing the problem…
@Moonloop
I highly recommend following Geoff’s suggestion. This way you can find out if a replacement of the SSD may be needed.
Connect the SSD via a hard drive enclosure, then plug it in to a USB port of a different machine to rule out system level malfunctions, original cabling and ports as a potential cause of this behavior.
Here is a link that might help convince you of this approach. Whether it is a Samsung or Crucial brand does not matter in this case.
I will remove the drive tomorrow and see if it makes any difference performance wise in an external caddy .
M
So , Day 5 of both Roon and RoonArc running smoothly with SSD connected from an external caddy , no dropouts , no error messages and no disappearing library so far . That’s the good news , is the bad news that the Nucleus+ is screwed ? I could hardly sell it on if it isn’t capable of handling an internal drive so I wonder if getting it serviced is possible though it is out of warranty ?
M
It seems likely that the SATA channel is screwed by something, and if this is not simply caused by a dicky cable, then it would be an expensive fix, i.e. replacement of the entire motherboard.
Personally, I would simply live with the SSD attached by USB; much cheaper.
I see what you mean but I’m still disappointed at a component costing more than £2.5k failing in this way. If ethernet goes next then it becomes a very expensive doorstop 
M
Hey @Moonloop,
@Geoff_Coupe makes a good point with the cheapest option being: maintain the SSD via USB.
That said, you could also try a different SATA cable and SATA port as well to test to see if the behavior was the same. If both were swapped out and the issue still occurs, it could be a situation with the SATA connector to the motherboard being loose. If that’s the case then only a motherboard replacement will fix it.
It is very strange because the unit is in a rack and is never moved .I doubt there’s a tech here that could sort it out anyway .
M
