MC7700 SED / BootHold mode

I have a large pool of MC7700’s installed in Panasonic CF-31’s. My clients are complaining that during natural use, the host will stop detecting the aircard and becomes unusable. Watcher and or Skylight report “No device Detected”. This seems to be random and happens in both Urban and Rural locations. However, most complaints occur from clients while driving in and out of coverage between towers. I have verified that while this is happening the physical wireless switch is not turned off. Also, the Software wireless switch utility is set to power on the Wireless WAN modem / adapter. However, the adapter is grayed out and not selectable during the event. Device manager does not show a connected modem / adapter during the event. And lastly, no AT commands can be sent to the modem during the event. The only resolution that we can apply is to reboot the system - causing a power cycle to the card.

From my testing, and after some reading, I believe that when the issue is present, the card is in Boothold mode, I suspect due to Smart Error Dectection (SED). As AT commands cannot be sent to the device during boothold mode, the only way to recover is a power cycle. The physical wireless switch on the laptop should due just that, but sadly it does not and the client is forced to reboot their computer.

Is there a way to disable SED or recover from Boothold with out a hard system boot?

Skylight version 6.0.4166.7806
Sierra Wireless WWAN Modem driver 14.2.1005.27
Sierra Wireless Mobile Boadband Network Adapter driver 14.7.1050.64
MC7700 firmware SWI9200X_03.05.20.05ap r5847 cardmd-en-10527

Hi Rpatrick,

Are you in contact with distributor or Sierra for the issue?

Normally, SED triggered during several consecutive reset.
In theory, it should not happens based on your description.

Still, to further understand, are you able to find “DM” interface under “Ports” section of Device manager after issue happened?

Also, may I ask which carrier/FW you used to repeat such problem?


Thanks for the Reply Louis,

The carrier is SaskTel and the firmware is MC7700 firmware SWI9200X_03.05.20.05ap r5847 cardmd-en-10527.
We also have three versions of drivers in play, with two versions of the sierra watcher/skylight. All three drivers work without issue on some machines. The machines with issue have ran the course of all three drivers. I should mention that in couple of cases, completely cleaning the system of both the drivers and GUI, then re-installing the same version has cleared the issue. However, this does not seem to work on all of the machines. Moreover, machines that didn’t previously have the issue, may in fact get the issue if we try upgrading the drivers.

When the event occurs, we cannot see the DM interface under ports in the device manager. Which is why I suspect Boot/Hold mode as the only way we can get the card to work again is to power cycle the host. This is similar to when we turn off the physical wireless switch, which pulls Pin20 low - forcing W_Disable_N to put the card into sleep mode. However, when the issue is present, toggling the physical switch does nothing.

Therefore, I have to believe the the driver is completely unloaded during the event. Otherwise the toggling the wireless switch should, for all intents, wake up the card.

We have placed this concern with Panasonic, the OEM, to see if they can determine why the event is occurring.