I have this Raspberry Pi 3 and I haven't used it in 2-3 months but I wanted to revive it by using it as a Home server. So, I booted it up with my Power supply and it tries to boot and after couple of seconds, it keeps on rebooting. I thought my power supply wasn't enough, so I tried it on my Raspberry Pi 2 and it worked fine! I even thought it was a problem with the SD card but it booted fine on my Raspberry Pi 2. Any help would be appreciated!