I was doing a project on a Raspberry Pi 2. Recently, something happened and now the board is not working. I'm planning to replace it with a RPi Model B+. Can I use the same SD card to boot without formatting it? Do I have to install a fresh OS on the SD card and install all other software, or can I simply insert the previous one and it'll work?
Presuming you are referring to Raspbian, the same SD card should work unless you have removed
kernel.img from the boot partition and/or corresponding directories from
If you are referring to an OS that is Pi 2/3 only (e.g., various forms of Ubuntu) then no, it will not work on a B+.
Also, if you have specified a specific kernel in
/boot/config.txt, then comment that line out. You can also check to see if one ended up there some other way.
That's "commented out" (
#). This way the bootloader will be able to select the correct kernel.