Mark II won't boot

Thanks for the hint on the flash drive - I started having the same symptoms the past few days, and the flash drive does indeed appear dead.

FWIW when I plug it into another host, it gets pretty warm compared to a known good one.

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Many thanks for the tip. I also replaced the flash drive, with the “stable” image downloaded from mycroft-software, and my Mark II is again up and running (though I did need to redo the configuration).

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I also observed that the very small SanDisk flash drives were getting quite hot. It’s one reason we went with a different drive when we purchased some to load our Neon OS on. They’re still small, but they’re metal on the outside, so they dissipate the heat better.

For those of you ordering a new drive, I suggest upgrading to an SSD. We’ve gotten faster performance of our Neon OS with one. It’s only a little edge for most of the on-device skills, but it boots faster and runs noticeably faster for skills that access external data sources. I’d be interested in hearing anyone’s experience who tries using an SSD with the Dinkum or OVOS OS.

On the flip side, I don’t recommend using a random old USB drive from the back of a desk drawer - I loaded our OS on one, a USB 2.0, and it was noticeably slowed.

Another troubleshooting suggestion is to try an alternate OS.

One user told me that he thought his issues were hardware, but when he tried booting his Mark II with our OS the issues were absent, so he was able to realize it was a software issue, not hardware.
If you are experiencing this boot failure, one option would be to test your Mark II with the alternate Mark II operating system “Neon OS”.

You can flash your own USB with the Neon OS that can be downloaded here at no charge: Neon AI OS for the Mark II | Neon AI
The Neon OS is a fork of the Mycroft OS, and is also open source software.
You can also order the Neon OS on a new 64GB USB 3 drive on Square for $19.95 - please note this is not a sales pitch since we don’t make money on this. Neongecko is a Mycroft AI Channel Partner and Mycroft Community Developer.

While its possible that the OS could be at play, I personally observed that the data storage itself was damaged; I wasn’t even able to create a backup iso of the drive. If it was an issue with data on the filesystem, i would have been able to create an image containing the corrupted data.

In general, flash memory has a relatively low number of read/write operations before it no longer can be used. Since thumb drives are more geared to infrequent writing of files, they lack the features SSD and more expensive sd cards possess. Its also worth adding that one such feature, TRIM/fstrim, requires support from both the hardware and software. I haven’t dug in to the mycroft iso, but its an area which could potentially be optimized in future builds.


Can you give us a link to the ones you chose?

Happy to share our info. We chose the 64GB version of these - USB 3.1 Flash Drive FIT Plus 128GB Memory & Storage - MUF-128AB/AM | Samsung US
The 64GB is out of stock right now on the Samsung site, but they’re also available on Amazon.

@devnill brought up an excellent point about flash memory having a limited lifespan. That’s something I’ve never had to consider before. I’m just starting down the research path on that, keywords are endurance & P/E cycles. So far, it looks like high temperature reduces the lifespan of flash memory, so switching to the small but metal USB we chose, an SSD, or if it won’t be awkward for you a larger metal USB should give it a longer lifespan.

If you find a choice that looks better than ours, and any more pertinent information, please do share that as well. :slight_smile:

If anyone wants to try an SSD, we shopped around a bit for a good value, and chose this one from among many good choices. I tested and am happy with it, so we set it up as an option on Square also. We’re not an Amazon affiliate.


I just wanted to re-share this post about the Sandisk

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mine is garbage and I can’t believe I paid money for this. it only boots sometimes and I had to buy it direct because I probably won’t ever see my kickstarter one.
holy crap I should’ve made my own with a raspberry pi.

FWIW, I went overboard and am currently running with this one:

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I don’t know if this is useful information, in that it may not apply to the image that’s on the flash drives that are failing and there may not be a way for an end-user to fix it even if it does–

When I set up classic-core on a Raspberry Pi a while ago I initially noticed that the disk access LED was flickering non-stop, and running iostat showed that a mycroft process was going bonkers writing and reading data to something in the /tmp directory. I enabled the tmp.mount service (since I built it on an Ubuntu base image) which mounts /tmp as an in-memory tmpfs file system and the disk access LED turned off. If I hadn’t caught that I suspect my SD card wouldn’t have lasted very long either. Maybe it’s possible something similar is going on with the Mark II image that appears to be killing USB drives.

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I believe you are seeing the mic_level ipc, this is used for the cli client to show the mic meter in the terminal

this was flagged ages ago and something we fixed in ovos, i was under the impression the mk2 branch (pre dinkum) also disabled this feature, there should be a mycroft.conf for it, but not in mycroft-core dev branch, sandbox images dont use dev but a mk2 specific branch so no clue about those…

in mk1 and picroft images i believe this used a ramdisk, you can set the path for this in mycroft.conf

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Looks great to me! I assume you’ve received it by now, have you noticed any performance improvements?

Also, just going to tag some folks from this thread here, want to make sure everyone saw that they can get a new USB from us for free and got one ordered if they’d like that. Here’s a link to our original posted offer - Neon AI for Mark II for free @Rudism @wingzeroalchemist @Ion9509 @colin @ashmanskas @scott.werner.vt

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Same issue here - Sandisk flash drive failed within the first couple of weeks.
Replaced it with a Sandisk USB 3.0 micro ssd adapter and 64 GB U3 / A2 rated micro ssd - much faster now!

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Also confirmed the thumb drive failed as it does not mount in OSX or Arch. I switched to the free USB disk provided by NeonAI and now up and running.

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After about 3 days of use my NEON hung and fails to reboot.

I’m putting part of my email response here, for the benefit of anyone else who might need similar troubleshooting. However, if you do, please drop me an @ mention or even better an email. Thanks!

Thank you for the screenshot. Basic troubleshooting, which I expect you’ve already done, would be to make sure only the Neon boot drive is connected and is plugged into USB port 0 (the blue one on the left - Tips - NeonAI® Documentation).

If it’s plugged in to the correct port, with no other USBs plugged in, then it appears your USB has become corrupted. Are you technical enough to re-image the drive with these instructions? I know it’s a bit of work you were probably looking to avoid by ordering the USB. If you have the time, it would be valuable to us to know if this fixes your issue. You will need to download our OS from here or the link here on our webpage, and download a free imaging program if you don’t have one already. We suggest Raspberry Pi Imager or Balena Etcher

Installation Instructions:
Plug your blank USB drive into your computer (use the one that’s not working)
Open Imager (we suggest Raspberry Pi Imager or Balena Etcher)
Under ‘Operating System’, select ‘Use Custom’
Locate and select the Neon image you downloaded
Under ‘Storage’, select your USB drive
Click ‘Write’ and wait for the image to be written and verified
Remove the USB drive and plug it into your Mark II
Plug power into your Mark II
After starting up, you will be guided through connecting to WiFi

I’m also available to walk you through this process on a tech support video call, if that would be helpful.

I see your USB order from a few days ago. Thank you for trying out Neon and providing this valuable feedback. Please keep me posted on how things go so I can make sure you end up with a working copy of Neon again.

What is the difference/function of the right hand USB3.0 port and the left one on the Mark 2?

No difference in function. However, on boot, the device checks first in the lefthand port for a boot drive, and then in the right. So, if you have a music USB plugged into the lefthand port, and your boot drive in the righthand one, it is likely it won’t boot successfully.


Thank you so much for that…it clarifies things for me.

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Thanks for the tip! Fan was on, but screen was dead. Pulled the power then removed the USB stick and tested in my PC, it doesn’t even register as a USB device. Working on flashing a new drive now, fingers crossed…

UPDATE: after flashing Neon, ring lights activated, but screen was still blank. Opened the front panel and re-seated the screen ribbon-cable and all is working once again.