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SysadminBJ
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February 21st, 2020 11:00
Latitude 5420 LTE Dropping
My company has recently moved towards the Dell rugged line for our field operations teams utilizing the onboard LTE chipset for field communications. In our first few deployments, we are starting to see a lot of issues where the LTE card will stop functioning altogether. This occurs most often when a USB device is connected to the system.
The USB devices all use virtual com ports and are data collectors for drive-by meter reading.
- Neptune MX900
- Hershey Street Machine (various versions).
- Neptune NGO data collector (the FSR was using the computer as a charging hub for this device).
My thought is that since the LTE card uses a virtual COM port, these devices are causing a conflict and causing the LTE card to go nuts.
Has anyone seen this? Any suggestions? Can I force the LTE card to use a COM port that will never be used by my USB devices?
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Posted February 28th, 2020 14:00
Out of curiosity, what cellular device(s) are installed in these E5420 laptops and who is the service provider?
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Posted March 2nd, 2020 05:00
The device is a DW5821e Snapdragon X20 LTE and the provider is Verizon.
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Posted March 3rd, 2020 19:00
@CraigFed I’ve had my Precision 7740 w/DW5821e since December and I haven’t observed any issues with mobile broadband hardware or software. It works equally well as my Precision 7520 w/DW5811e. What issues do occur are with Verizon Wireless and those clear up on their own. With what limited things I can monitor I don’t see anything that might suggest a problem. In the past, Verizon’s implementation of IPv6 was a bit flaky, you might try disabling IPv6 and then rebooting to see if performance consistency is affected.
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Posted September 23rd, 2020 06:00
I'm starting to have this happen with several of my 5420's. All of a sudden cellular goes offline and then you look in device manager and the snapdragon has an error on it from timing out. Only rebooting or reinstalling the device seems to work. I tried disabling and reenabling and it didn't do anything.
Have you had any luck since you first posted this?
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Posted November 19th, 2020 09:00
I received the following information from the Latitude team. They asked me to post this out here for them.
Ensure that the latest drivers are installed.
Dell Wireless 5821e/Qualcomm Snapdragon X20 LTE Firmware and GNSS Driver
* Only uninstall the old drivers using the Windows Apps & features and not from the Device Manager
* Device Manager changes =
- Disable/Uncheck the “Allow Windows to Turn off this device to save power” on the WWAN card* Windows Power Management change =
- Advanced Options > USB Selective Suspend – Disable
DELL-Chris M (old account)
#IWork4Dell
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Posted November 19th, 2020 09:00
Chris, You're a hero. You have no idea how many of my guys have been complaining about this. They have been restarting their devices to get it to turn back on again. I had done the driver updates before and it seemed to prolong how long before it would happen again, but not totally fix it.3573
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Posted November 19th, 2020 10:00
It happens due to windows managing the power settings for devices. It is configured that way for a lot of devices. If any other device exhibits such behavior, always check in the device manager for that particular device to see if there is a power management option and then turn it off.
#IWork4Dell
For all non-technical issues that require your private data, we must communicate via a private Direct Message
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Posted June 23rd, 2021 14:00
I have a similar problem with Latitude 7400 since Windows 10 21h2.
Microsoft Update did push drive updates, supposedly from Dell, and the LTE one failed. So, I removed the drivers and reinstalled the latest from Dell Support Homepage, but now the LTE seems to restart again and again.
And in 21h2 all the ways described in all the tutorials out there fail.
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Posted August 1st, 2023 09:00
Hey Heinrich_k, have you gotten a fix for this issue? Thanks.
CraigFed
2 Posts
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Posted February 28th, 2020 07:00
We are having the same issue, cell connection drops on Latitude 5420's. We purchased 60 of these machines and about 20 are having the same problem. The only USB device in use is a brother pocketjet printer. We have found three methods of resolution. The first is to take the sim card out and re-seat the card. The second is to uninstall the snapdragon device from device manager and restart the computer. The third is to reinstall the driver. This will restore the cellular connection temporarily. The issue has been recurring on several of the machines and the above 3 methods of resolution fix it until it happens again. We have been in contact with a dell rep for resolution but very little progress has been made so far.