Boron assertion failure - MODE button unresponsive

I am experiencing an issue where a boron fails in our fleet, and upon receiving it back for inspection, the device is flashing SOS red led 10 times (assertion failure according to documentation). This may seem similar to this thread I found, however in my case I am NOT able to do anything that requires the mode button (no safe mode, no DFU, no factory reset), when powering the device on holding the mode button, it just instantly begins blinking red.
To add a bit of context, I had a device come back a few months ago with this issue but I noticed an issue with the other electronics in the unit, and although it did not seem to be something that would have any impact at all on the boron, I did not think it would make sense to spend time debugging a device with an error I only ever saw one time in a unit that had another defect. Unfortunately I just got another unit back with the exact same behavior. I still have the original failed unit as well so I confirmed that both are having the exact same issue, and both seem to ignore any input with the mode button. My main interest is finding out the CAUSE (so that I can hopefully prevent it going forward) but would also be interested in any proposed solutions if anyone can think of any (I have a particle SWD/JTAG debugger if that matters). One of the devices was running 2.0.0-rc.3 and the other was running 1.4.2, and both ran for months without firmware changes before failing.
Thank you!!


As you already received a replacement, it is highly unlikely and unfortunate that you keep encountering this issue. Is the same application code on both devices? As you are an experienced user, you might be aware that the red blinks might be due to application heap and memory overflow: Status LED and Device Modes - Boron | Tutorials | Particle

Feel free to tag me on this post so there is an alert for me to check your response. Thanks.

I see you logged a ticket. I will handle this ticket. Looking forward to working with you. Thanks.