Re: R7450 Brick?
Sometimes it takes a few attempts as its a short window when you use tftp. I usually use the windows built in client successfully.
are you on windows? if so, follow this guide
just make sure you enable tftp
and here's a video walk through using a tftp client. Use the built in one for windows 10 though. the video is more of an example of how its done.
and if that doesn't work, you can try using nmrpflash