Wireless Joint

This tutorial will demonstrate a fairly easy way to restore the Sierra Wireless modem COM port using a Windows machine. While I will be working with the Sierra Wireless MC7750 modem, the same procedure worked for the MC7700 and will most likely work for other Sierra Wireless modems.

As with all the tutorials, use at your own risk.

You will first need to download and install the latest Sierra Wireless drivers for Windows. This is allow Windows to communicate with the modem.

I came across a Sierra Wireless MC7750 that lost its modem COM port. The only port available was the DM COM port. In later modem modems this stage may be referred to as QLoader mode.

This is what we see when using the Huawei Terminal:



When you download the MC7750 firmware from Sierra Wireless, the download contains two files: the modem firmware .cwe file, and the FlashTool.

Needless to say, the flash tool when used, offers little help since it cannot properly detect the modem:





We will unzip/extract the MC7750 firmware flashtool. Right click the exe firmware and extract its contents.


Create a new folder and place the MC7750 firmware .cwe, the fdt2.exe, the combo_script.txt and the GobiApi.dll files into the new folder. Next, execute the fdt2.exe application by double clicking the file:




And, give it a few minutes to do its job.




After the firmware is updated, press the ENTER and the modem will go off line. Be patient and wait a minute or two, then unplug the power to the modem.

Wait a few seconds and plug the power back to the modem.

When the modem reboots “completely” (give it a couple of minutes if necessary for the drivers to load), you can check to see if the modem COM port is now available.

You can test the Modem COM port by entering the ATI command. If it will not accept the command, reboot the modem and reflash it again using the steps above.


Next, just to assure the firmware did flash correctly, we will reflash the firmware using the MC7700 OEM firmware kit. This may or may not be required, but I generally err on the side of caution. And it sure easier to do it now than have to redo it later.




Again, while you are there, test out the modem port with the ATI command:




Done!

None of the firmware packages I can find have the combo_script.txt file in them. See below for the error I get when trying to flash without it.

FDT version: 1.0.1804.0
Awaiting suitable port or adapter ...
Switching to streaming mode ...
Enabling selective suspend ...
Firmware download failed.
Primary error code: 76 - Failed in switching device to streaming download mode.
Secondary error code: 73 - Received NAK response in DMSS download protocol.
Device error code: 0x0 - Unknown device error code.

Preexisting images information:
Current:
Firmware:
ImageId:
BuildId:
Configuration:
ImageId:
BuildId:
Final images information:
Current:
Firmware:
ImageId:
BuildId:
Configuration:
ImageId:
BuildId:

OEM PRI:

IMEI:

Total time elapsed: 8562 ms.


Images downloaded:


Press Enter to continue ...

Let me look though some files when time permits and see what I can come up with.

Thanks, getting this thing up would be a big help.

Not 100% sure, so you REALLY NEED TO run this by Jim before using... Not positive on the path=%temp%\FDT. Best to get his blessing before using.

Think the combo_script.txt file simply contains:

terryjett wrote: Sat Nov 23, 2019 9:24 am Not 100% sure, so you REALLY NEED TO run this by Jim before using... Not positive on the path=%temp%\FDT. Best to get his blessing before using.

Think the combo_script.txt file simply contains:

Code: Select all

;Auto =generated, do not edit
Setup=fdt.exe -f 1584083_999999_MC7750_03.05.10.13_00_vzw_033.012_000_SPKG.cwe
path=%temp%\FDT
Silent=1
Overwrite=1

Tried adding that since I haven't heard anything back from Jim and same results. So I'm stuck with a useless device until I can make this thing work again.

DJDD4551 wrote: Mon Jan 06, 2020 5:46 pm Tried adding that since I haven't heard anything back from Jim and same results. So I'm stuck with a useless device until I can make this thing work again.

You can give this one a try.