I have few units of SL8082T while upgrading from R7.50.0.A1 to 7.52.1.A5 on a few of the modules. the Update didn’t complete successfully. and now on ATI3 it will show
"Sierra Wireless, Incorporated
SL8082T
APP3
This looks like the bootloader is still alive. The bootloader only understands a couple of at commands and replies OK or ERROR to pretty much everything else.
You should be able to attempt to reflash the firmware using the at+wdwl command and a 1k xmodem downloader.
Have a look in the release notes for instructions on doing a serial flash update. This should work even though you miht be connecting across a usb port.
You might have to go back a couple of versions to find the instructions though.
Worst case, your distributor should be able to recover these using some of their internal tools.
In my experience ~10% of SL808xT modules fail to upgrade cleanly, corrupting the flash memory and causing the module to endlessly reboot.
I’ve not had any success in recovering them, despite trying numerous methods.
This must be a common problem, even if SW don’t publicly admit to it, because the the latest 7.53.1.A1 firmware includes some improvements where the module will detect successive restarts and enter a state where the corrupt flash memory can be overwritten.