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Fanfold Paper
Posts: 23
Registered: ‎04-09-2018
Location: US
Views: 1,365
Message 1 of 3

t480s WWAN challenge



My brand new T480s is giving me a rough time already. I bought it with the Fibocom L850-GL modem and inserted an AT&T sim.


Today I wanted to upload 14 files totaling about 1.66gb over cellular as the upload speeds are much better in town than they are on the home internet. Also I have 48gb of data on the plan so let's ignore that.


First question, why does it keep changing the network back to metered mode? Every time I turn cellular off and back on it's again marked as such. Even if the connection drops briefly and comes back on its own it is again metered. One drive refuses to upload on metered connections until I go into it and hit resume. If the connection drops briefly one drive pauses again as it is again metered.


That's the first, and the less troublesome, issue believe it or not. The real problem I have is, once I do have one drive uploading, I can get speeds according to one drive of around 2.6 or 2.7mb/s. It'll do that for about 4 minutes or so, till it reaches around 80 to 100mb transfered, then the computer will just hickup and stop responding for a few seconds then come back, and now one drive is uploading at 0.0kb/s and my computer starts getting hot.


Looking in task manager, I see that system is using 99 percent of the cpu, I'm talking about the system process and not speaking of some process running under the system account just to be extra clear. Btw I'm using a port of the windows 7 task manager, I don't like the windows 10 one, too sluggish.


So, it's a glitch, I think to myself. I kill one drive, system continues going nuts. So I reboot, all is good. I unpause one drive and watch it start from scratch again (hate that) and it gets to around 80 to 100mb and does the same thing. I look in task manager and it's using over 90 percent cpu again. This is the core i5 3.4ghz thing.


So, I reboot yet again and try it yet again, exact same thing. And btw, I checked in task manager and system was using 0 like it should before I let one drive do it's thing. Note also that system continued to use 0 until this weird glitch thing where the computer lags out and one drive suddenly stops working, then that's when it starts eating all it can get.


The real pitty is, this is mostly what I bought this computer for, my yoga2pro was having issues but I was able to get the keyboard repaired, a battery replacement installed and the WiFi upgraded so now I really need the T480s to be working perfectly in order to justify this 1900 bucks.


I'm suddenly just about tempted to return it, but I really, really think Lenovo shouldn't hit me with the darn restocking fee as this won't be an I don't like it issue it's an it doesn't work like it should issue.


Ug, I'm sure if I call Lenovo about this it'll be reformat your system, it's most assuredly your fault.


Only thing I have done is delete the lenovo pm device driver and disable windows form automatically installing device drivers so it wouldn't come back. That being so, do you suppose I'm looking for a modem driver update? I did get one before I turned driver installs off, but.


Still why the heck would system do that. I haven't had the chance to try letting resilio do my uploading to see if the glitch goes away if it's not just one drive.


Thanks all, here's hoping somebody out there knows something. I'm at a loss, I might as well just use my phone's hotspot and the yoga2pro.

Fanfold Paper
Posts: 23
Registered: ‎04-09-2018
Location: US
Views: 1,288
Message 2 of 3

Re: t480s WWAN challenge

Anybody out there?

Had the same problem with resilio. Not nearly as quick, ran for maybe 10 minutes before it went. Same thing after that, system started using 100 percent of the available cpu to the point that I only barely managed to make the system reboot without having to hold in my power button.

As outlined in this other thread
I can't get the driver to change so I can try troubleshooting that way. help somebody? I'm very close to just returning this thing, if I can't use cellular my Yoga2pro does just fine especially now that I have a new battery and keyboard.
Fanfold Paper
Posts: 23
Registered: ‎04-09-2018
Location: US
Views: 1,201
Message 3 of 3

Re: t480s WWAN challenge

I'm pasting below an exact copy of the paper attached to the back of the repair instructions form in the box with my t480s as it goes in for depot repair service tomorrow if we can find a fedex. Unfortunately, I missed the return window because I thought I cleared up this problem but I didn't and now I'm pretty depressed about this whole cluster f, to tell the truth about it. It's hard to reproduce it on purpose, because I have to take a 10 mile ride into town and get really good signal and upload for a while. unfortunately, when I want it to happen, it behaves itself and just doesn't quite upload fast enough to cause the hang, 1.9mb/s is probably going to be ok for hours, it's 2.8mb/s or so that makes it go sideways. When I need it most, that's when I'll get lucky and get really, really fast speeds out of it for a bit, exactly what I need when uploading that big humongous audio recording I need to back up off site, and boom, bye bye cellular. It is so powerfully frustrating. I'm really patient with computers and such, but this is so blatently a problem with exactly one of the things I need to work perfectly that I totally have regrets about ever even thinking about buying a new computer right now.


Begin paste:


Problem Description:
After uploading at file transfer rates of 2.8mb/s or more for more than 10 minutes or so continuously over the LTE connection with an AT&T sim inserted, system disconnects from LTE and becomes very hot and sluggish. The system (system) process shows a cpu usage of nearly 100 percent under Windows Task Manager and the machine has 0 percent idle. The machine is so sluggish it is nearly impossible to initiate a reboot to solve the problem. Occasionally, the system (system) process only uses a single cpu thread after the cellular disconnect occurs, for a total of around 12 percent cpu usage as reported by task manager, when this happens. However, in spite of the fact the system doesn't become sluggish when the 12 percent senario occurs, a reboot is still required to get cellular back, because while turning cellular off in the network flyout on the notification area does cause the system process to start using 0 percent cpu again, cellular will not come back on if I attempt to switch it back on in the network flyout until a windows reboot. After rebooting, the issue shows up again after several more minutes attempting to upload with excellent cellular signal on the LTE band.

I have reproduced it 8 or so times in various locations. The only constant factor is that the upload speed has to be very fast (2.8mb/s or more), thus the hang is only going to show itself with excellent cellular signal and a high bandwidth LTE connection, which is exactly what I want to take advantage of the modem for. I have always used it with AT&T.

Note that to reproduce, one needs a high upload speed capable service e.g. resilio sync, one drive.

Note also that I can connect this machine to my android phone's hotspot and upload at the same or greater speeds in the exact same locations with no issues.

Note finally that the modem driver version won't change when I attempt to install a new driver. The version shown under device properties in device manager for the modem is not consistent with the version claimed on the driver download from the Lenovo website. Also, I can't uninstall the driver. It disappears when I do so but returns immediately when I scan for hardware changes within device manager. Additionally, the data rate claim in the status option under change adapter settings is not consistent with the claimed data rate capabilities of the adapter.

Please site the two following related Lenovo Community forum threads

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