MC8705 not enumerating Ports

Hi All,
We have a strange issue where by some of our MC8705’s are not enumerating as they should do (Window 7). We are using a USB adapter which has been checked by using another MC8705 and all the ports show up.

When we plug in the MC8705s that have the issue all we see is one port - the CNS port (UMTS) is enumerated :frowning: anyone have any ideas why this has happened and if there is a way to make them work again !

Many thanks

what exactly are you doing?? is it like you are trying to download FW and the issue happened?? in that case, module might be locked in bootloader mode… can you try to download the FW again and check if the ports are enumerating?

If the issue is only in windows?? Are you able to see the ports in Linux??


We have the same issue with the disappeared COM ports at MC8705. This behaviour occurs with some MC8705 cards.

After restart (coldstart and rebooting System) sometimes the COMports are not present except for the one port (CNS).
We did not make any udpate procedure, it just happens by normal work.

It seems that sometimes the module hangs up during starting up. Is there an issue concering the bootloader etc.?

How can we fix this problem?

Thanks for any help


Are you able to see this issue on both Windows and Linux?


Hi Alex,

we work only with Windows-OS.
Therfore we we cannot give any response concerning issues with Linux.

But as I have already written, this issue is present at some of the modules, others work fine and this issue never occurred.
So it could be more an issue located internally in the module by differences (other components etc.)


Hi Alex,

we have the same issues under Windows 8: Most of the modules work fine, but some modules enumerates only one port. Not each time, but random after 2 to 5 power cycles. If I downgrade the module to an older firmware (ATT then the issues does not occur (more than 30 power cycles tested) !!

Is a new firmware version planed by Sierra Wireless ?


Edit: Version corrected

Hi Alex,

the actual version is The next downloadable version below is the In the release notes are some versions between these two listed. Are these versions available ? We would like to find the first version below without the not enumerating Ports issues.