I cannot guarantee whether “every” board needs to do this flash because the factory may already updated their image on product line.
If you plug your sdcard on it and the boot log stuck somewhere before booting into kernel, then it is probably that incompatible issue. Dump the serial console log may help tell this case.
You are using the latest SDK Manager? So should I just take all my devices and update the bootroms with the SDK Manager? Which part of the flashing process does this take place?
Yes, I use the latest sdkmanager. Actually, if you already installed sdkmanager once, you could just use the flash.sh under “Linux_for_Tegra” folder on your host to do the flash and it saves time.
sudo ./flash.sh -r board_name mmcblk0p1 (-r means reusing the existing system.img)
You have to write the correct board name for jetson nano. The quick start guide on download center could teach you how to use flash.sh.
And you could refer to flash.xml under Linux_for_Tegra/bootloader to check what partitions are on QSPI while others are on sdmmc (sdcard).
Unfortunately this part cannot be separate so flash will also erase and update new content on your sdcard. You have to be careful. If you have some important data on sdcard, you could firstly follow the instructions in this page to do the cloning.