Restore Quectel EG25-G module after SixFab Core

Raspberry Pi Network HATs 3G/4G&LTE Base HAT
1

Hello everyone!

I installed SixFab Core, and then I decided to uninstall it. To uninstall, I used the command sudo bash -c "$(curl -sN https://install.connect.sixfab.com)" -- --uninstall, which I found in the F.A.Q. section on SixFab’s website. I also reinstalled Modem Manager, but the command mmcli -L outputs “No modems were found,” while the lsusb command shows “Bus 003 Device 005: ID 2c7c:0125 Quectel Wireless Solutions Co., Ltd. EC25 LTE modem.” What’s most strange to me is that mobile internet continues to work even though SixFab Core has been uninstalled, there are no modems listed, and there are no active connections in Network Manager. Additionally, after checking the service “core_manager.service” using the command sudo systemctl status core_manager.service, I see the message “Unit core_manager.service could not be found.”

After rebooting the Raspberry Pi 5, I noticed a new internet connection called “Wired_connection_1” appeared on usb0 but then disappeared, and mobile internet continues to work. Modem Manager now detects the modem, and the command mmcli -L outputs “/org/freedesktop/ModemManager1/Modem/0 [Quectel] EG25”. Before installing SixFab Core, it was “/org/freedesktop/ModemManager1/Modem/0 [QUALCOMM INCORPORATED] QUECTEL Mobile Broadband Module.”

I have a spare Quectel EG25/EC25 Mini PCIe 4G/LTE Module, so I replaced the old Quectel EG25/EC25 Mini PCIe 4G/LTE Module with the same model, and everything worked as before. I didn’t change anything else—same firmware, same SIM card, same Sixfab 3G – 4G/LTE Base HAT for Raspberry Pi, I only replaced the Quectel EG25/EC25 Mini PCIe 4G/LTE Module. The command mmcli -L now outputs “/org/freedesktop/ModemManager1/Modem/0 [QUALCOMM INCORPORATED] QUECTEL Mobile Broadband Module”, and I can manage the mobile internet connection through Network Manager just like before installing SixFab Core. This suggests the issue lies with the Quectel EG25/EC25 Mini PCIe 4G/LTE Module.

How can I restore my Quectel EG25/EC25 Mini PCIe 4G/LTE Module after SixFab Core? Is it worth reflashing it now?

My setup:

  • Raspberry Pi 5
  • Sixfab 3G – 4G/LTE Base HAT for Raspberry Pi
  • Quectel EG25/EC25 Mini PCIe 4G/LTE Module
  • SixFab SIM card
2

I have resolved my issue. The problem was that after installing and removing SixFab Core, the modem switched from QMI mode, which it was originally in, to PPP mode. I discovered this after connecting via minicom on my Raspberry Pi and entering the command AT+QCFG="usbnet". In response, I received +QCFG: "usbnet",1, indicating that the modem was operating in PPP mode. I switched it back to QMI mode by entering the command AT+QCFG="usbnet",0 and rebooted the modem with the command AT+CFUN=1,1. After rebooting my Raspberry Pi, the modem was once again recognized as /org/freedesktop/ModemManager1/Modem/0 [QUALCOMM INCORPORATED] QUECTEL Mobile Broadband Module, and I can now manage the mobile connection through Network Manager.