MC7750 and the Verizon: occasional disconnect

My product uses a MC7750 running on Linux 2.6 kernel, connected to the Verizon commercial LTE network in the US. What we are experiencing, seemingly on both 1.0.9 firmware and firmware, is that sometimes after sitting idle for 10 minutes or more, the unit disconnects from the Verizon network. We have not seen this behavior before in other modules or other networks.

If we are transmitting data continuously through that time, we don’t seem to have the issue.

I see that the MC7750 does not seem to have a built-in connection watchdog and see some evidence that other modules based on other chipsets do. I was curious about anyone else’s experience with the MC7750 and disconnects: is there some sleep or power setting I am overlooking? Are you experiencing similar problems? Is a software-based connection watchdog advisable or always required? Etc.

Any information is greatly appreciated!


It seems the module is going to Low Power Mode. is it?


Not according to qmicli and the get state command, while the modem is exhibiting this behavior, that command still returns “online”.

But, let me ask anyway: is there a setting on the MC7750 for when to toggle to the low power state and a way to disable such a feature of so? It would still be worth the try…

I don’t have any useful information to offer on an answer, but we have seen this same problem with the MC7750 and Verizon. Our firmware version is slightly out of date, so we are working with our FAE to get a newer release and test that out.

Newer than, or you mean you are updating to to see if that resolves it? Thanks, its at least affirming to know its not just us!

We’re in the process of upgrading to So it may not do anything, but at least we’ll be in the same sinking ship. :slight_smile:

The upgrade didn’t seem to help. We’re still noticing the disconnect problem, too.

I’ve escalated it with our FAE, but there is no word on a theory yet. If I hear anything, I’ll post it here.

For archive purposes, we’re running a Linux 3.4.42 kernel with the QMI SDK 03.00.02 and Gobi drivers S2.9N2.11. Both the SDK and drivers have been patched for various issues found and reported on this forum.


That is a big help to know Chris let me know what your FAE says and of course I will post any new data here as well.


We have new CF19’s MK6’s with the MC7750 internal air cards. We have been seeing some of the similar issues as well. However, we were able to narrow it down to he internal air card will not turn on after a system shutdown and power up. We can restart the toughbooks all day, and the air card will come up every time. We are also seeing the random disconnect issue. It will just show the network adapter as unplugged…

In order to get the air cards to turn back on after a system shutdown, we have to login as local administrator, and as soon as the see the desktop, the air card light is on. Then we can restart the system, and login as a domain user.

I find it hard to believe that I would have bad air cards in all of these Panasonic toughbooks.

We have updated to the latest firmware update and no fix…

Thanks! Happy trails!