MC7750 QDL / EDL Mode 05c6:9008 - Hard Brick ?!

Hello everyone. I want to share a weird state of my MC7750. It shows up in QDL - maybe even EDL - mode as 05c6:9008. FW Download does not work with qmi-firmware-update or firmware tools in Sierra SDK. So I ended up using Streaming DLOAD Tool from openpst · GitHub.

Here I always get a response with 0x03 at the second response byte. I assume that a severe error occured.

Dumping 5 bytes written
7e 0b ab 4e 7e                                    | ~..N~
Dumping 7 bytes read
7e 03 00 06 9e 4c 7e                              | ~....L~

Does anybody have had a similar case and can help classify this error shown above?
BTW.: What you see is a HDLC dump, but I was not able to “read” it due to missing information.

Hi simsum,

Using an unofficial tool to flash FW to the module may cause unexpected issues. Could you please try with FDT tool on Windows?


Hi jerdung, the excerpt is not part of a flash procedure. It’s a simple NOP (NoOperation).
The official Sierra SDK was already used but with no success. The same response part 0x3 was detected by Sierra’s firmwareLite DownloadTool and qmi-firmware-update. (0x7e is HDLC header / trailer.)
The windows FDT.exe Tool cannot even recognize the already entered QDL/EDL state.