Hello I have a rb 450g and when I power on, it only makes one beep and I can’t enter by mac or ip.I hope that an expert in repair routerboard tell me what can I do to fix it.
Put some screwdriver (or anything metal) into the hole, apply power and wait until it boots. You will need to open the router…see video.
https://www.youtube.com/watch?v=G-iIxxXcYq0
What firmware and routeros did you have on it?
I had a similar problem with 6.30.2 and FW 3.24. After downgrade to 6.27 (as far as I remember) if failed to boot (1 beep).
Screwdriver on power up for a second or so (meaning backup bootloader) + FW “upgrade” to 3.22 solved the problem.