@koga 

Hello，

Please help me to confirm the following information, thank you!

1. Did you mean that when you connect to the 5G network, the T3U will crash? If so, at this time, what is the LED light status on the T3U? 

2. When it crashed, is there any error information? If so, please send me a photo of the error information, thank you!

3. When it crashed, did you need to install the driver again? Or you can need to unplug and plug the T3U to make it work well again?

4. If you install it again, how long are you able to use the 5G? And how often did it happen again?

5. When you connect to your router's 5G network, are you able to get a stable connection from it?

6. Please try to plug the T3U on another computer, then check if it can work well.

7. Please refer to this FAQ to check your settings on your computer and router:

https://www.tp-link.com/en/support/faq/2253/

If it still has this issue,

1. Please tell me what troubleshooting steps you have done.

2. Please help us check the driver version of adapter and computer motherboard info and send us the photos: https://www.tp-link.com/en/support/faq/2722/

3.The model number of your router

4. How long did you have the device and when did the issue start?

5. If there is another computer available, please test the adapter on a different computer

6. If you are the Q3 situation in the FAQ, may I have a photo of the Error message?

Thank you for your precious time. 

Wish you a nice day.

@Kathy_Z 

Hello, thanks for your quick help !

Here are my answers :

1 - Yes, exactly, when i try to connect to the 5Ghz, the T3U crash and I'm no longer able to see the networks. At this time, the LED light status is off.

2 - No, There's no error message, I just can't use the wifi anymore ( just like the T3U is not recognized anymore).

3 - Yes, i need to install the driver again, and i need to unplug the T3U because it isn't recognized by the driver.

4 - I'm not able to use 5G network , or it crash when i'm trying to connect to it.

5 - I'm not able to use 5G network , or it crash when i'm trying to connect to it.

6 - I don't have another computer, but i will try this weekend.

7 - I've already check this FAQ, when i tried to connect to the 5Ghz with my phone, it works well. Plus, with my old computer, I was able to connect to the 5Ghz.

1 - I have reinstalled the driver (my computer is new so it is unlikely that a software is the cause of the malfunction)
     I modified the parameters of my router to change the 5Ghz channels (my 5Ghz network became visible from that moment on)
     I have tested the connection on all channels (I can't connect to any).
     I tried plugging the T3U into all my USB ports.

2/3 - I'll send you the info this weekend.

4 - I got the T3U since 1 week, end the issue start at the first install.

5 - I'll try this weekend.

6 - I d'ont have any error message.. the T3U disconnect and that's all.

Hope it will help you !

Wish you a nice day.

@Kathy_Z 

here are the driver version of adapter and computer motherboard info 

@Kathy_Z 

Here also my router info :

Wish you a nice day 

@koga 

Hi, really sorry to hear that you have this issue.

I have checked your issue from our senior engineers.

Please follow the instruction to install the adapter on your PC with the below driver manually to check if the same issue happens again. https://www.tp-link.com/support/faq/920/

https://static.tp-link.com/2019/201911/20191128/00011389-RTLWlanU_WindowsDriver_1030.29.1102.2017_DUA_tplink_0719.L (1).zip

If the issue is the same, may I know your region?

Since you just bought it one week ago, have you saved the purchase proof?

Look forward to your reply.

Good day!

@koga 

Excellent! 

@Kathy_Z 

Hi,

I have encountered a problem, there is no .inf files in the downloaded zip and so i can't follow the instructions of the manual installation guide.

It is also specified that not every driver contains an inf file so i conclude that there is no inf for the Archer T3U ?

Now i'm asking myself how it is possible that the author could do this manual installation without the .inf file.

I have the same issue and i really want to be connected to my 5ghz network.

Look forward to your reply.

Good day!