@David-TP 

David, thx for your reply. My deco was working GREAT until I updated the firmware through the deco app. I got no errors in the deco app during the FW download or during the FW upgrade. It is the latest FW version for deco, just released tp link offers.

Firmware Version: Deco XE75(US)_V2.6_1.1.1 Build 20230327

I can't tell you the ver # because the deco app never connects to the main deco unit, which stays red. My ISP is Conexon, but again my deco was running GREAT until the FW upgrade or the FW upgrade process (deco app) bricked my deco. I have worked with my ISP & confirmed my modem is online/up, while my deco is offline/red/bricked.
 

Im guessing this is pretty common issue with the deco FW upgrade...What's the fix?

Thx

  @HarryTP I have the same problem.  Everything was working perfectly with WiFi to the whole house.  Updated the firmwear and now I have nothing.  I have reset the main deco multiple times but it keeps telling me there is no ethernet cable connected.  There is and when I plug the ethernet cable directly into a laptop the internet is working perfectly.  Like you, this firmwear update appears to have broken my whole deco mesh system and I don't know how to sort it.  I've reset the main deco and tried to set up a whole new system but just when you think it's going to work the deco turns red and nothing except another reset will change it.  I've spent hours going around in circles.  I can't see how I can install a fix for the firmwear update when the main deco will no longer connect to the internet.  Not happy at all.

  @David-TP I have followed the instructions in both the links you provide as a suggested fix for this issue and neither has solved the problem.  My mesh system still will not connect to the internet.

David-TP wrote

  @HarryTP 

Hi, welcome to the community.

May I know who is your internet service provider?

When the main Deco XE75 turned red, could you please check on the Deco APP>more>internet connection>IPV4 to see whether there is still a valid internet IP address?

Do you need to restart Deco again to restore the internet connection? Or will unplugging the internet cable from the modem and plugging it back in be able to get Deco back to green?

Here are some suggestions for your reference:

1. Clone the MAC address of the old WIFI router to the main Deco XE75.

How to Configure MAC Clone on Deco

2. Change the WAN DNS to 8.8.8.8/8.8.4.4

How to change DNS server settings on my Deco

 

Wait for your reply.

Best regards.

 

  @HarryTP Thank you for your help but sadly it hasn't worked.  My Deco app won't even save the network.  Every time I go into the app now it wants to set up a whole new network.  It's just going around in circles; sets up a network then says no ethernet cable connected (there is!!) but the network itself is there.  Then, when I try again, the network has vanished and I have to start again from scratch (reset deco unit and set up the network again).  The internet is working perfectly when I connect the ethernet cable direct to my laptop so I know that's not the issue.  We have 6 or 7 deco units (big house with thick walls) so quite some monies worth of kit which I'm beginning to think is now obsolete due to this latest firmwear update!!!! Thanks again.

Nick, I forgot to say that once I was able to get connected to my Main deco again I clicked on the plus sign in the deco app top corner & created an entirely new network, that network is up & I have blue lights on both decos (I only have two).

If you want to try this, I have no idea if it will make any difference, try a different phone and/or delete the deco app from your phone, reinstall it again on your phone or on a install the deco app on a different phone. 

  @HarryTP Thanks again Harry.  I've had to click the plus sign every time to set up a new network (which it never saves).

I've also deleted and downloaded the app again and logged out and back in but nothing at all works unfortunately.  I'm hoping someone from Deco might be kind enough to respond or the whole mesh network which was working perfectly prior to the firmwear update (!!!!) will have to be replaced at great expense.  Not to mention the time I have already spent trying to sort it out.

  @David-TP I have sent you a message with information asked for.  Thanks.