As users Israel and noeliestj have already stated, your best bet is to try resetting the Echo, or to send it to warranty service. If you would like to repair it on your own, it sounds like your LED/Microphone board and the power/speaker driver board are malfunctioning and should be replaced.
"After I dropped my echo I had the same issues. I took the echo apart, all the way down to the bare parts, then put her back together again making sure the ribbon connectors were nice and tight, and she came back to life- lit right up.
After a power failure, I reset with the pin hole in the bottom first. Then I had to set up my Echo as a "new device", and then have her discover the lights etc again. All back on line now.
