Hi, before check its warranty, here are some tests you can run:

a. ensure that you can get internet from the main router with the same cable/port.

b. Try to hard reset the camera by holding the reset button. 

c. Change another cable and another port to give it a go.

Still the same, may need reach out to their tech support to check the warranty. 

Hi all, I have this same issue, trying to connect via Ethernet to router, its a Virgin Media Hub 3.0 with 2.4 ghz/5 ghz dual network.  Ive tried all the reset options, cables, etc and still have a red flashing light!  Any help would be appreciated.  The item is new and straight out of the box.  Thanks,

Anton L.Z. wrote

Hi, before check its warranty, here are some tests you can run:

a. ensure that you can get internet from the main router with the same cable/port.

b. Try to hard reset the camera by holding the reset button. 

c. Change another cable and another port to give it a go.

Still the same, may need reach out to their tech support to check the warranty. 

Ensure that you can access internet from the main router by wired cable first. 

And then try to power cycle it and hard reset it, if still the same, you may contact their tech support to confirm whether the device is faulty and check the warranty service. 

https://www.tp-link.com/en/support/contact-technical-support/#Hotline-Support