Fix LT400 EU V2, LT450 EU, LT500 EU & LT500D EU V2 no internet issue

Note: This article applies to the LT400 V2, LT450, LT500 & LT500D V2 sold in European stores only.

Recently, we've received a lot of feedbacks that many of our clients can't access the internet with their Cudy routers, despite their SIM cards being functional and their APN settings being accurate.
Here is a method we have discovered that could help with the issue.

Step 1: Update the router to the lastest firmware version. 

If the firmware is already the latest version. You can skip this step. If not, Please download and unzip the official firmware.

Download Center

Open a web browser and go to or, Then log in. For details, please refer to How to log into the web interface of Cudy Router?

Upgrade the firmware in Advanced Settings->Firmware.
How to upgrade the firmware of Cudy Router?

Step 2: To download and upgrade the module firmware, please contact to obtain the upgrade firmware. At the same time,  download the Diagnosis bin file in Diagnostic Tools->Diagnosis->GO->Download and send the file to the support.

Step 3: Enter the address below in the address bar. Upgrade the firmware as video shows.

Step 4: When the update is complete, it will return to the System Status. Go back to the hide Firmware Upgrade page and check if it's successful.

If the problem persists, go to Diagnostic Tools->Diagnosis->GO->Download and send the bin file to