Debian Hardware :: T420 Random Reboot / Kernel Panic

I have had a serious problem with my laptop recently. I have been having unexpected reboots and kernel panics and I don't know why. I can't tell if it is hardware or software, and what is causing it.

It has happened on multiple power bricks from different outlets and locations, my slice battery and my main 9-cell battery.

I am running Debian Testing/Stretch with Kernel 4.1 with XFCE4 on a Lenovo T420 with 16 gb of ram, a i5-2540m, USB3 Express Card, OCZ SSD, an intel 7260 ac wifi card and Ericcson F5521GW 3g card. I also have a modded bios for the wireless cards, and I have had that for over half a year without any problems.

I have no clue what the cause is from the logs.

I also booted into Windows for a bit, then it blue screened, but I don't know if it was because of a driver I had tried to put on earlier for the 3g card, because Linux was out of commission and I needed 3g. The driver didn't work, gave a code 10 or something and gave me a blue screen that said something along the lines of device driver attempting to corrupt the system has been caught. Windows also won't boot anymore.

I'm not worried about Windows though, and what I really need is Linux to work, being that this was the first time I booted up into windows in several months.

Memtest runs fine, and passes all tests.

Right when I turned on my computer after one incident, I wrote a script to check the CPU temp and write it to a file every second. Once the computer turned off, I read the file and it said the CPU was at 39 degrees. Not something to turn off over.

I cannot find any indication of a problem in /var/log/kern.log. kern.log was extracted from the computer right after it rebooted randomly. Find it here: [URL] ...