Note, this content came from reddit (https://www.reddit.com/r/homeautomation/comments/eul2au/did_amazon_finally_brick_my_repurposed_dash/).
Saved here for posterity.
I wanted to add a little bit to this tonight after messing around with the five buttons I purchased on eBay. I've ended up with three bricked buttons after 'taking one for the team' but here's what I've got.
The following sites are blocked in PiHole:
dash-button-na-aws-opf.amazon.com
dash-button-na.amazon.com
parker-gateway-na.amazon.com
Just put them in your Blacklist and that should be it.
The 'bricked' firmware appears to be 60019520_WS. My non-bricked units are still running 50018520_WS. My buttons are all part number JK29LP -- I'm not sure which version this is. Interestingly the one that seems to have paired correctly and acts like a true 'button' has CE0682 in large print on the back while the others that paired only have the large CE logo.
How do you get the firmware, you ask? Easy! There are two ways: a) put it into WiFi configuration mode and connect to the AP, go to http://192.168.0.1 in your browser and you'll see it. Option b) is to use the setup-dash.py firmware below -- it will show the firmware when you configure wifi.
To easily set the WiFi information, you have two options:
Option 1: Put the unit into pairing mode by pressing and holding the button until it flashes blue. Connect with your computer to the "Amazon ConfigureMe" access point and once connected, go to http://192.168.0.1/?amzn_ssid=&amzn_pw= (replacing and where required). The button will reboot and your computer will reconnect to WiFi.
Option 2: Download the setup-dash.py python script here: https://gist.github.com/fffonion/d4960503ff6782640286163d47a30080. I'm using this on a Mac (requires sudo) but it accepts two arguments: SSID and Password. If you have non-standard characters, be sure to escape them. It will guide you through basically the same setup process as option 1. The beauty of this method is you get the MAC address so you can watch your DHCP server for whatever IP it gets.
You can watch your DHCP server and you should see the IP that the button will get. You can then ping the button IP and when it press it you should see one or two pings come back.
Ways your button can flash:
Slow white flash followed by three red flashes - Ready for wifi setup
Solid red followed by three red flashes - bricked
Solid blue (10 seconds) followed by a solid red (2 secs) then three red flashes - bricked
This was the first one I was playing with so I think it is in some other undocumented mode. Either way it appears to be unrecoverable.
Slow white flash followed by multiple red flashes (6 or so) - Ready fo IoT funzies! This button should be on your wifi network but cannot connect to AWS cloud.
Quick white flash followed by multiple red flashes (10-12) - Ready for IoT funzies as well! Still cannot connect to the cloud.
Hopefully this helps some people out -- I know its a bit of a scatter-brained mess. I was working on it as I was messing with the buttons. I still think these are a great bit of kit that still deserves to get to some kind of good use, even if it is just looking for ARP requests and doing small web requests.
Reply from reddit.
Very good writeup. I was looking for something to unbrick the button. Unfortunately couldn't find anything yet.
The crazy method of registering an unpaired dash with sound via headphones you didn't mention so I just want to add it here: https://blog.christophermullins.com/2019/12/20/rescue-your-amazon-dash-buttons/ - unfortunately that also doesn't unbrick. Wouldn't it be great to update the firmware via sound?