EM20 not connecting

[zlever]

Hi,

I have an EM20 with the m.2 to usb3 adapter and can not get it to connect. I started with the rooter firmware with the EM20 patch in my router (archer c7), but it just hangs on connecting.

The sim card info is available but no connection. I moved over to a Windows 10 machine to test the card, and I get no service.

I posted on the Facebook group, and Jim mentioned putting the card in LTE mode. I tried this with no luck. I've tried a Sprint and Visible sim card and get no service on the Windows machine.

My old modem, MC7455, will connect with the Sprint and Visible sim cards in rooter and Windows 10.

I've also tried a clean install of the rooter em20 patch with no luck. Any ideas? Thanks.

[JimHelms]

I have an EM20 with the m.2 to usb3 adapter and can not get it to connect. I started with the rooter firmware with the EM20 patch in my router (archer c7), but it just hangs on connecting.

I assume all the fields on the Network status page is populating correctly, and it does read the SIM Card?

The sim card info is available but no connection. I moved over to a Windows 10 machine to test the card, and I get no service.

I am not an advocate of trying to connect (to the internet) on a Windows machine, a modem to be used behind a router. I have seen Windows cause strange behavior to include changing the composition of the modem.

I posted on the Facebook group, and Jim mentioned putting the card in LTE mode. I tried this with no luck. I've tried a Sprint and Visible sim card and get no service on the Windows machine.

Yes, placing the modem in LTE only is the only way I have successfully connected using Sprint. Also, are you certain you are using the correct APN that the device uses for the particular Sprint plan (i.e., n.ispsn vs r.ispsn)?

If I was having issues connecting, I would also place the SIM back into the device/hotspot and update the user profile and any other updates that is available--prior to trying to connect it behind a router.

I've also tried a clean install of the rooter em20 patch with no luck. Any ideas? Thanks.

Assuming the router is reading the SIM Card properly, and the proper APN is being used, and you have access to the AT Command port via ROOter, I would first remove the SIM Card, and set the modem to OEM. That will give you a fresh start.

To place the Quectel modem in OEM status, enter the command:

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AT+QPRTPARA=3

Give it about 10 seconds, then power down/unplug the modem and power off router.

Then, insert the SIM Card, and power everything back up.

Then, place the modem in LTE only:

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AT+QCFG="nwscanmode",3,1

When everything comes back on line, and it still does not connect, run the following commands and post the results:

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AT+QCFG="nwscanmode" 

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AT+QENG="servingcell"

[Didneywhorl]

What Jim said.

[zlever]

Still no luck.

AT+QCFG="nwscanmode"
+QCFG: "nwscanmode",3

AT+QENG="servingcell"
+QENG: "servingcell","LIMSRV","LTE","FDD",310,260,250A20C,97,900,2,5,5,7786,-118,-15,-83,13,5

Thanks.

[Didneywhorl]

What APN are you using?

I would stop swapping it between Windows and the router, as well as stop swapping SIMs. Stick with the Sprint SIM, they tend to be easier to deal with. Keeping on one rig we are familiar with will help with troubleshooting.

What is the Sprint SIM out of? What plan?

I have zero clue why but I find when using the usb adapter with r00ter, I have success entering the APN in both the Connection Profile page as well as the Network-->Interfaces-->wwan-->edit-->APN

Also what mode is it in?

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AT+QCFG="USBNET"?

[zlever]

My APN is r.ispsn. I double-checked the apn when updating the profile in the original hotspot, which is the ZTE Warp Connect. The Sprint service is through Community Connects.

I've stopped using windows after Jim's instructions.

AT+QCFG="USBNET"?
+QCFG: "usbnet",2

I've added r.ispn to wwan. On the interface page I noticed "Error: Unknown error (NO_REGISTRATION)" on wwan and wan1.

[zlever]

I wondered if it was an antenna issue, so I unplugged two small omni antennas from m1 and m2 and left my panel antenna (MARS MA-WA25-DP17B 17dBi) connected to d/g and m. I rebooted and have a connection now. Speeds are slow though. 2-Mpbs compared to ~20Mpbs with the MC7455. I'm going to try to reposition the panel antenna.

[Didneywhorl]

Ahhhhh!

You mixed a wide band antenna with a narrow band antenna! I dont think that's a good idea. I could totally be wrong, but I do know the EM20 does not use the same frequency ranges on the main pair versus the second pair. Ill have to look it up.

Let us know how re-aiming the panel works out. I use 2 dual panel narrow band antennas on mine for B41 use, connected to my em20.

[Didneywhorl]

Your last at+qeng="servingcell" says your were connected to B26, which your flat panel cannot use.

What is the servingcell info now with the flat panel only?

[zlever]

I was connected for about 10 minutes on B41. The signal was 32%. I adjusted the antenna and rebooted and haven't been able to reconnect, even after adjusting the antenna back to the original position. I'm wondering if it's just a weak signal that is causing connection issues.

Right now with just the panel (with no service): "servingcell","LIMSRV","LTE","FDD",310,260,250A20C,97,900,2,5,5,7786,-117,-15,-82,13,6

With the same panel on the MC7455, I was getting 60-70% signal strength on B41.

Also, I've noticed that if the EM20 is powered off, It doesn't keep the LTE only setting, I have to re-enter AT+QCFG="nwscanmode",3,1. Is that normal?

[Didneywhorl]

Tell me what firmware is it using, the em20?

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ATI

[zlever]

ATI
Quectel
EM20
Revision: EM20GRUR01A08M4G

[Didneywhorl]

Yeah, Im not sure why but I also have to reset my nwscanmode on my em20 everytime I power down

I gotta ask the r00ter guys why that is. Im certain its a router thing.

[Didneywhorl]

Run

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AT+QRSRP

for me please

[zlever]

AT+QRSRP
ERROR

[Didneywhorl]

Hmmm

[BillA]

AT+QRSRP
ERROR

Based on your serving cell info +QENG: "servingcell","LIMSRV","LTE","FDD",310,260, looks like you're either roaming on the Tmobile network, or Sprint has changed their MCC/MNC to 310/260 (normally it's 310/120). It should't matter since now they've merged, just though it might be interesting to point it out. For testing purposes, you could try to disable roaming to see if it makes any difference via the AT command.
To disable roaming:

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AT+QCFG="roamservice",1,1

To enable auto-roaming:

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AT+QCFG="roamservice",255,1

[zlever]

looks like you're either roaming on the Tmobile network

Interesting.

AT+QCFG="roamservice",0,1 gives me an error.

[BillA]

Interesting.

AT+QCFG="roamservice",0,1 gives me an error.

First try to read the current roam settings. If you get an error, then it's either not supported (unlikely), or there's some issue with your modem communication (likely).

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AT+QCFG="roamservice"

Then try to disable roaming:

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AT+QCFG="roamservice",1,1

To enable auto-roaming:

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AT+QCFG="roamservice",255,1

You could also try it without the ",1" at the end, which just tells the modem to activate the setting without rebooting, so just reboot the router after sending the command.

To disable roaming:

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AT+QCFG="roamservice",1

To enable auto-roaming:

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AT+QCFG="roamservice",255

[zlever]

AT+QCFG="roamservice",1,1 worked, but I'm still unable to connect.

Current serving cell with roaming off.

AT+QENG="servingcell"
+QENG: "servingcell","LIMSRV","LTE","FDD",310,260,250A20C,97,900,2,5,5,7786,-118,-15,-83,12,5

Still looks like a t-mobile tower.

[BillA]

AT+QCFG="roamservice",1,1 worked, but I'm still unable to connect.

Current serving cell with roaming off.

AT+QENG="servingcell"
+QENG: "servingcell","LIMSRV","LTE","FDD",310,260,250A20C,97,900,2,5,5,7786,-118,-15,-83,12,5

Still looks like a t-mobile tower.

In that case looks like Sprint has changed their MCC/MNC (310/120) to Tmobile's 310/260 which is fine given their merger, your issue probably lies elsewhere. By the way, it doesn't hurt to have roaming off, it just prevents the modem to roam onto an unapproved network to avoid data roaming charges. If you wish, you can set it to back to auto-roam.
It may be caused by your weak signal -118db ("LTE","FDD",310,260,250A20C,97,900,2,5,5,7786,-118,-15,-83,12,5), try a good high gain external antenna, either an all-in-one or a pair.

[zlever]

Thanks.

Interestingly, on the MC7455 with the same sim and antenna, it connects to a sprint tower.

S

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ignal Information
Network : LTE	 
CSQ : 16	 
Signal Strength : 51%	 
RSSI : -81 dBm	 
ECIO : -10.9 (RSRQ) dB 	 
RSCP : -113 (RSRP) dBm 	 
Connection Monitoring Status : UP (+) (using Ping Test)

Cell Information
MCC MNC : 310 120	 
RNC/eNB ID : CB94B (833867)	 
LAC/TAC : 7786 (30598)	 
Cell ID :43 (67)	 
LTE Band : B41 (Bandwidth 20 MHz)	 
Channel : 41374	 
Maximum Qos : --

I got a second panel antenna yesterday. Just waiting on the cables. I noticed the EM20 firmware downgrade posted in another thread. I'm wondering if I should take that route.

[punkguy00017]

I'm having the same issue got a wg3526 with wifix and modem gets stuck at connecting

[BillA]

Thanks.

Interestingly, on the MC7455 with the same sim and antenna, it connects to a sprint tower.

I got a second panel antenna yesterday. Just waiting on the cables. I noticed the EM20 firmware downgrade posted in another thread. I'm wondering if I should take that route.

I've read about some connection issues with the EM20 and GoldenOrb/WiFix, and one of the suggestions was to downgrade the modem's firmware, or wait for the new firmware release with proper modem support. Honestly I'm not too familiar is that modem or downgrading it, but here's a post about it > https://wirelessjoint.com/viewtopic.php?f=16&t=1225

I was just thinking, maybe one of the those fragile MHF4 may have cracked slightly from the circuit board, which could cause the poor signal. You'll find out with the better antennas. Or maybe it needs a firmware upgrade or downgrade, and the least likely scenario it's possibly defective.

[Didneywhorl]

The mass agreement for now is to downgrade the firmware of the EM20 modem to the A06 firmware version. Jim's writeup is written well.