@Ralph_alpha Hello, 

Sorry for the late response, do you mean the 5Ghz signal becomes very weak on the computer using Archer T3U Plus, what is the signal strength on 5Ghz right now? 

How about the 2.4Ghz Wi-Fi signal on Wi-Fi adapter? 

You could try a different Wi-Fi channel for 5Ghz to channel 36/40/44/48 and see if that helps.

Please uninstall your current driver and install the driver on official driver here:

https://www.tp-link.com/support/download/archer-t3u-plus/

@Ralph_alpha Hello, 

Thank you for your update! For your previous description, T3U could detect 5Ghz Wi-Fi, but the signal is very weak right ?

For 'its both 5GHz and 2.4GHz that are not connecting.'  do you means both 2.4Ghz and 5Ghz signal are very weak, or you could see the wifi signal with full bar but it will not connect to that wifi, what is the Error message when you try to connect to that wifi? May I have a photo of the Error? 

Do you have different computer, please also install the chipset driver and try T3U on it. 

@Ralph_alpha Hello, 

Sorry for the delayed reply, the signal is too weak and this could be some hardware issue on your adapter. 

• You could enable hotspot and see if signal is also very weak on your computer.
• You could try this adapter on a different computer if got one, if signal is still too weak, sorry for tell you this adapter is broken.

It  is recommended to contact local support or retailer to check warranty for it. 

Your understanding is much appreciated.