I assume it is the cable from the modem to the router. Power off the modem and router, use a different good quality cable, power up the modem and wait for it to stabilize, then power up the router.

Hey, I am facing the same issue since yesterday evening. My AC1200 was working fine, suddenly in the evening it randomly switched itself off, after that I unplugged and plugged it back, it started but then again switched off. Then I realised, everytime I plugged internet cable into it, it turned itself off. Did you resolve your problem, how did you do it? Thanks Ashutosh

@Ashutosh.k 

 

The original poster never replied back if the cable solved the issue or not.

 

When you say that every time you plug the internet cable, it shuts down, is it the cable to the modem or one to one of your devices?

 

Try a different cable.

 

Check the connector and see if you have any bent pins. Be sure there is no stress on the connection.

 

Ensure the router is getting enough air to keep it cool as heat can cause power down.

 

Be sure you are using the correct power adapter (the one that came with the router).

 

 

 

 

@ArcherC8 thanks for the reply.

 

I am using the same internet cable with my old modem(digisol) now that AC1200 is not working, and the same cable is working with digisol so cable seems to be good.

 

The power adaptor is what came with the router, it's also from tplink, so that is good.

 

I will have to check the bent pins. 

 

The router is now cool and I will now check if it works.

 

But a working router suddenly stopped working in the evening, is strange to me.

 

Anyway, I will reply on this thread.

@Ashutosh.k 

 

Those were the common things that can cause that issue. Here are a few more.

 

If you get it pluged in and powered up, try wiggling the cable.

 

Do you have any USB devices attached? If so remove them as a test. If the USB devices pulls to much power, it can power down the router.

 

Also try a factory reset.

 

Since you have another router, can you try to set it up as an AP to the other router as you would be using the LAN port instead of the WAN port.

 

The router may be going bad. I hope not.