EM7455 doesn`t work in DELL tablet

Hello my name is Azamat and I am from Kazakhstan. I noticed strange problem with DELL tablets. We bought 11 tablets. After connecting and using providers LTE we couldnt to connect to our Private LTE network with BAND 20. I guess EM7455 saved previous setting. If you connect firstly sim card of private LTE it works. Also I couldnt type AT command because MBIM. I updated drivers, windows 10, and rolled back windows but it doesnt help. Is it anybody else who faced the same problem?
How I can reset EM7455 modem ro default ? Greetings from Kazakhstan and Please help me.

Hi @nurjigitov.azamat

That means the device has successfully connected to another private LTE before. And then you change SIM, private network and it can’t connect to LTE network, right?

Have you tried to set the APN to the APN of your private LTE network in the “Cellular” settings (Settings → Network & Internet → Cellular → Advanced options → Add APN) before connecting to the network?

As for the AT command, the AT command port is different from the MBIM interface, so MBIM does not affect to type the AT command . You can search for “Device Manager” on Windows, the port for the AT command will be displayed in the Modems tab. You can use this port to type AT command.


Hello Donald. Thanks for advaices, Yes I set up new APN it didnt help. Also I cant find a com port in Network adapter


Could you help me what is next step ?

Hi @nurjigitov.azamat

Driver you installed, is it the driver of Sierra? if not, you can install the driver for EM7455 at Sierra source page (https://source.sierrawireless.com/resources/airprime/software/airprime-em_mc-series-windows-drivers-qmi-build-latest-release/#sthash.NdNieNHI.dpbs). Check again and share your result about the connection and com port are in “Device Manager”.
Another way, you can change the APN by Skylight tool of Sierra (Skylight Windows Connection Manager for EM/MC series modules). On the Skylight tool screen, Option icon → Profiles → Add new profile icon and then adding infomation for your APN network → Apply, after that, you can try to select new profile (next to Option icon on Skylight tool screen) and then connect.

Beside that, can you provide the FW version with PRI you are using for EM7455 and your DELL tablet model? And the your EM7455 should be updated to latest FW.