WG3526 connection problems - no signal, AT!GSTATUS? fails

[xdavidx]

You are probably in QMI composition mode. Try this:

AT!ENTERCND="A710"
AT!USBCOMP?

*Note: Be very carful not to put an = after the AT!USBCOMP command. You don't want to accidentally change it to a wrong value.

The AT!USBCOMP? will give you the current composition. If it is QMI, then that's probably why you can't swap the image, as I had that same issue just the other day and found that I could only do it when I switched to MBIM mode.

Your AT!IMAGE? command shows that you are set to slot 255, so something is very weird there. It should be 1, 2, 3, or 4. Unless 255 is some special mode. The command references don't document the AT!IMAGE? command, so that type of information isn't available (at least not in those documents).

[xdavidx]

I also just noticed that your firmware build numbers don't match your carrier configuration (the PRI lines) in the AT!IMAGE? results. One of them matches your preferred firmware build number and the other one matches your current firmware build number. Something doesn't seem right there.

Sprint is the only one that matches. When the modem was at The Wireless Haven, GENERIC and SPRINT matched (but AT&T and VERIZON didn't). Now GENERIC somehow got unmatched.

Similar situation here, regarding low power mode and failed firmware flashes: https://forum.sierrawireless.com/t/em75 ... -mode/9836

There is an AUTO-SIM mode that is supposed to switch the firmware based on the SIM that is installed. Maybe that mode got used at some point on this modem and it is still having an effect, even though IMPREF isn't set to AUTO-SIM. I only mention that, since the sim was once in a VERIZON device, so might have left over VERIZON "stuff" on it.

Just an idea, but if you go through the process of switching the image to GENERIC and it doesn't stick again, swapping that SIM for a new one is another thing to try.

Resetting back to factory defaults is another thing to try, but I'm guessing that would be the last thing you'd want to do after everything you've been through.

[thebranman]

I also just noticed that your firmware build numbers don't match your carrier configuration (the PRI lines) in the AT!IMAGE? results. One of them matches your preferred firmware build number and the other one matches your current firmware build number. Something doesn't seem right there.

Sprint is the only one that matches. When the modem was at The Wireless Haven, GENERIC and SPRINT matched (but AT&T and VERIZON didn't). Now GENERIC somehow got unmatched.

Similar situation here, regarding low power mode and failed firmware flashes: https://forum.sierrawireless.com/t/em75 ... -mode/9836

There is an AUTO-SIM mode that is supposed to switch the firmware based on the SIM that is installed. Maybe that mode got used at some point on this modem and it is still having an effect, even though IMPREF isn't set to AUTO-SIM. I only mention that, since the sim was once in a VERIZON device, so might have left over VERIZON "stuff" on it.

Just an idea, but if you go through the process of switching the image to GENERIC and it doesn't stick again, swapping that SIM for a new one is another thing to try.

Resetting back to factory defaults is another thing to try, but I'm guessing that would be the last thing you'd want to do after everything you've been through.

Thanks for the info. The iPad Air was originally on Verizon a few years ago but had been unlocked since then. I used that device after it’s service was cancelled to setup the att data account with the att sim card, since I thought it wouldn’t be an issue. The sim hasn’t been back in that device since initiating the at&t data plan.

I’ll try the amigo/mbim mode Genereic switch you mentioned now..thanks! Crossing fingers

[xdavidx]

I had to switch to MBIM and do a reset and then switch to a different firmware and do another reset (like Jim showed). After the second reset for the firmware change, the modem couldn't be found in the status screen. I waited maybe 15 or 20 seconds and then did a router software reboot.

I haven't tried again to verify, but there is a chance it was just taking that long to do the firmware swap. So after setting to generic and resetting, you may have to wait a while for it to show up in the status screen. I would give it several minutes before doing a router reboot.

[thebranman]

Similar situation here, regarding low power mode and failed firmware flashes: https://forum.sierrawireless.com/t/em75 ... -mode/9836

Thanks for the link. Here are all my recent results from those you mentioned to try:

Code: Select all

AT!USBCOMP?
Config Index: 1
Config Type:  1 (Generic)
Interface bitmask: 00001009 (diag,modem,mbim) 

OK

Code: Select all

at!pcinfo?
State: Low Power Mode
LPM voters - Temp:0, Volt:0, User:0, W_DISABLE:0, IMSWITCH:1, BIOS:0, LWM2M:0, OMADM:0, FOTA:0
LPM persistence - None

OK

I tried the commands they listed in the link as well, and am getting the same error as before when Jim mentioned a similar series of commands. One thing though, the poster listed <password> and wasn't sure what to put in there, but most likely would be A710, no?

Code: Select all

AT!ENTERCND="<password>"
AT!IMPREF="GENERIC"
AT!RESET

Another mentioned "It didn’t worked with the AT commands, however manage to fix it with the Connection Manger (Skylight) settings. Still wondering what was the reason for the modem to go in the LPM mode." in that thread...but not sure what Connection Manager is.

Thanks David!

[thebranman]

I had to switch to MBIM and do a reset and then switch to a different firmware and do another reset (like Jim showed). After the second reset for the firmware change, the modem couldn't be found in the status screen. I waited maybe 15 or 20 seconds and then did a router software reboot.

I haven't tried again to verify, but there is a chance it was just taking that long to do the firmware swap. So after setting to generic and resetting, you may have to wait a while for it to show up in the status screen. I would give it several minutes before doing a router reboot.

I am already in MBIM mode now, but I guess I can try another router firmware/reset series...Ive done that a few times now. When you mention 'setting to generic', are you speaking of the command mentioned earlier? Thanks again

[thebranman]

I think I’m done messing about with this thing and am going to send this modem back to the pits of eBay (and add disclaimer of programming difficulty, of course) I accept defeat on this one, but I am so frustrated to not find out the cause and a resolution. Thanks to everyone who pitched in to help...it’s just not worth the wasted time.

Time to buy a brand new modem..never again buying a used one!

[JimHelms]

I would find a PC that the modem has never been attached to, download a fresh install of the Sierra Generic software drivers for Windows, and download all the carrier firmware executable files, and flash the modem twice with each of the carrier's firmware.

And, make sure there is no SIM Card in the device, and do never allow Windows on that PC to Manage the modem or internet connection.

[xdavidx]

Thanks for the link. Here are all my recent results from those you mentioned to try:

Code: Select all

AT!USBCOMP?
Config Index: 1
Config Type:  1 (Generic)
Interface bitmask: 00001009 (diag,modem,mbim) 

OK

Code: Select all

at!pcinfo?
State: Low Power Mode
LPM voters - Temp:0, Volt:0, User:0, W_DISABLE:0, IMSWITCH:1, BIOS:0, LWM2M:0, OMADM:0, FOTA:0
LPM persistence - None

OK

Okay, so you are definitely in MBIM mode. And the reason you are in low power mode is because of the image preference mismatch (IMSWITCH:1).

I tried the commands they listed in the link as well, and am getting the same error as before when Jim mentioned a similar series of commands. One thing though, the poster listed <password> and wasn't sure what to put in there, but most likely would be A710, no?

Code: Select all

AT!ENTERCND="<password>"
AT!IMPREF="GENERIC"
AT!RESET

Technically, IMPREF doesn't require you to enter the password first. USBCOMP does. But yes, A710, with double quotes, is the correct value, unless it has been overridden to something else. You were able to run USBCOMP, so the password is correct.

Another mentioned "It didn’t worked with the AT commands, however manage to fix it with the Connection Manger (Skylight) settings. Still wondering what was the reason for the modem to go in the LPM mode." in that thread...but not sure what Connection Manager is.

That's Sierra's Windows software for managing the modems when they are connected to a Windows machine.

It seems your root problem is that your images are jumbled in NVRAM.

[xdavidx]

I am already in MBIM mode now, but I guess I can try another router firmware/reset series...Ive done that a few times now. When you mention 'setting to generic', are you speaking of the command mentioned earlier? Thanks again

Yes, I mean with the AT!IMPREF="GENERIC" command. My guess is that your configuration for the GENERIC firmware and the image for the GENERIC firmware don't match, hence the issue. If so, then it seems you have to flash that firmware in a way that replaces both the configuration and the firmware image to matching builds. Alternatively, you could flash the firmware image that matches the configuration build to get them back in sync.

[xdavidx]

I think I’m done messing about with this thing and am going to send this modem back to the pits of eBay (and add disclaimer of programming difficulty, of course) I accept defeat on this one, but I am so frustrated to not find out the cause and a resolution. Thanks to everyone who pitched in to help...it’s just not worth the wasted time.

Time to buy a brand new modem..never again buying a used one!

Don't give up yet! You're in the home stretch!!

Here is another thing to try. You've already done the following:

Code: Select all

AT!ENTERCND="A710"
AT!RMARESET=1
AT!RESET

Instead of that, this time, try:

Code: Select all

AT!ENTERCND="A710"
AT!RMARESET=3
AT!RESET

That will set it back to the latest saved point. That is automatically saved after a successful image switch or external firmware update. You said it worked for 30 minutes, so maybe that will get you back into that state. If it flip flips again after 30 minutes, that's a whole other thing, but if you can get it running for 30 minutes at a time, then there is another thing you can try.

[thebranman]

I would find a PC that the modem has never been attached to, download a fresh install of the Sierra Generic software drivers for Windows, and download all the carrier firmware executable files, and flash the modem twice with each of the carrier's firmware.

And, make sure there is no SIM Card in the device, and do never allow Windows on that PC to Manage the modem or internet connection.

I will do exactly that, thank you...I will give it one more shot tonight, as im heading to a wife's friends house who has a PC. Hard to find in the world of Apple these days

crossing fingers..

[BillA]

I will do exactly that, thank you...I will give it one more shot tonight, as im heading to a wife's friends house who has a PC. Hard to find in the world of Apple these days
crossing fingers..

Any news on your success or failure? Please let us know what happened, and the exact steps you've taken so we can all learn from it. It seems like the Sierra MC7455 modem is little more finicky than the newer EM7565, and also the Quectel EP06-x cards, since I've never had any issues with the later two. It really helps to have an external Mini-PCIe/M.2 to USB adapter for flashing and testing purposes.