If you search the internet you'll find more cases like this. People update the OC200 firmware and it get's bricked.

Unfortunately a lot of them need to return their OC200 for RMA/warranty, because it can't be fixed with new FW.

 I just got one unit to try, and seems most of us have the same issue. I hope a fixed will be available soon.

  @Theo74 hope your device is not dead, if it is dead you can ignore my comment.

The guide from https://community.tp-link.com/en/business/forum/topic/270472 includes only a part where you set static ip on your router, in case it is not bricked, there could be several other possibilities, as example you manage it with cloud controller, it may have got different ip address from dhcp server which not only results in not being reachable under known address but some functions like mesh would stop to work to.

The guide should include step by step setting of static ip or dhcp reservation on dhcp server to ensure that device gets same address, all clients in the network get over dhcp info where cloud controller is which also would stop working.

Depending on where your dhcp server is, you can check there to resolve the issue but if you run it with omada managed router, then probably the quickest way to find it would be to run on any linux machine something like arp, this as example: arp -n

arp should show ip's and mac addresses (not all devices show mac address) which lets you easily find your controller in case it simply got different ip address.

In case that it is dead, you have to send it to tp-link for reflash, but even that you could do by yourself with little soldering skills to get serial output.

  @btx 

The link you posted above I've done, and completed with succes. Only the OC200 kept offline.

In my Omada router I gave all connected Omada hardware, and some LAN connected hardware, a fixed IP address.

In this case the OC200 would be set to factory default after it's recovery FW update, and then it's in DHCP mode. 
Then the Omada router would provide the OC200 it's reserved fixed IP witch it would accept, but that not happening.

Connecting the OC200 directly to the Omada router, instead of via the switches, made no differences, still offline.

Using a network search tool showed all present hardware, exept the OC200.

Because my OC200 is a half year old, my dealer arranged a RMA, and I will get a new one. He's convinced it's bricked.

  @Theo74 But it means you do rely on dhcp providing oc200 correct address, where on your pc you set static ip to be sure to have correct ip and access device, same should be done with oc200. You did not say if you changed oc200's ip to any other from default one, but in case you did, your oc200 might get wrong address despite having it defined in dhcp reservation, this happened to me already few times. Simply running arp would show all devices connected and if your oc200 is not dead and receives address then you would be good, however, as RMA is in process you are anyway on safe side by replacing device.

  @btx 

Although the RMA is in progress, I could give it another try...

Would you be able to give me a link and a simple instruction, how to search for the OC200's IP via this so called 'arp'?

To be honest, I'm not that good in IP networking. And, I've got both a Windows laptop as a Macbook Pro available.

Theo74 wrote

  @btx 

 

Although the RMA is in progress, I could give it another try...

Would you be able to give me a link and a simple instruction, how to search for the OC200's IP via this so called 'arp'?

To be honest, I'm not that good in IP networking. And, I've got both a Windows laptop as a Macbook Pro available.

 

Gladly, arp is a binary/executable which you run from command line:

1. open cmd with "Start->run" or click start and type cmd.

2. type arp and press enter

For more info about how to use arp on windows you could follow this link: https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/arp

Best if you you disconnect all other devices so that only your pc, router and oc200 are online, then you will be able to find it much faster. Also make sure to have set static ip on your pc, especially if your lan is in another than default subnet.