Quectel RM520N-GL modem - Wrong mode? Not connecting to T-Mobile

[tilde]

The first pair of these ZBT Z2101AX routers with Quectel RM520N-GL modems I ordered function fine and connect to T-Mobile without issue, but the three I just received do not connect to 4G LTE or 5G, either on the ZBT AC-Link firmware (forked Lede 17.01, not very modern) or when running this OpenWRT image: https://github.com/lusciousdark1975/zbt ... t-firmware

I haven't figured out how to get socat for this older Lede 17.01 build, it seems to not be in the packages directory: https://downloads.openwrt.org/releases/ ... /packages/ but echo seems to work to send AT commands (though I can't see the result :c). Recommendations for socat alternatives are welcome!

The vendor firmware is the same 22.08.08 across all routers, and comparing backups from all 4 routers doesn't reveal noteworthy differences. Is there an AT command to run on the modem itself that will encourage it to register to T-Mobile? Below are the cellular stats shown in the vendor firmware, signal being blank and cops showing no service are concerning.

First Router:
"device_model":"Quectel RM520N-GL",
"version":"RM520NGLAAR01A05M4G",
"sim_status":"READY",
"signal":"",
"iccid":"redacted",
"imsi":"redacted",
"imei":"redacted",
"cops":"No Service",
"cgreg":"Not registered",
"apn":"fast.t-mobile.com",
"net_type":"",
"usbnet":"+QCFG: "usbnet",0"

Second Router:
"device_model":"Quectel RM520N-GL",
"version":"RM520NGLAAR01A05M4G",
"sim_status":"READY",
"signal":"",
"iccid":"redacted",
"imsi":"redacted",
"imei":"redacted",
"cops":"No Service",
"cgreg":"Registered OK",
"apn":"fast.t-mobile.com",
"net_type":"",
"usbnet":"+QCFG: "usbnet",0"

[tilde]

This issue was solved by getting an R15 T-Mobile SIM.

[vigilant]

I'm having a similar issue.

I have a 502Q-AE and it's able to connect to 4G just fine but as soon as I enable any 5G it fails to connect to the network...
Wiredly enough it's able to still attach to the network but just fails to connect to the APN..

I try putting the sim on an my phone with same IMEI and it's able to connect just fine.

[guest00x]

Try changing the protocol to MBIM or QMI.

[xfx77]

or when running this OpenWRT image: https://github.com/lusciousdark1975/zbt ... t-firmware

I have the same router and am curious how you were able to flash firmware to it? I uploaded it to the router and it does a checksum ok but never seems to flash it after I hit proceed. I also tried the factory reset method of flashing to no avail, again it just seems to hang.

[xfx77]

I was able to get the unit flashed.. the firmware is not the best for sure. Was there a better alternative to AT commands than echo?

[Dazed-and-Confused]

I have the ZBT-Z6001AX running OpenWrt Chaos Calmer 15.05.1 22.1101_141831 and kernel 4.4.60. I don't think it will ever be supported by Rooter.

I had the RAM upgraded to 512MB for a small fee.

I use a RM510Q-GL in an external adapter with an RJ45 port and I hook that up to the router. Works fine, but dated firmware.

[Cruz40]

I have the zbt-z2101ax and was able to compile a Rooter build for it based on Rooter AB22: 22.03.2 was able to flash it through U-boot recovery. So far so good.

[GreyWolf23]

I have the zbt-z2101ax and was able to compile a Rooter build for it based on Rooter AB22: 22.03.2 was able to flash it through U-boot recovery. So far so good.

I recently purchased a ZBT model Z2101AX-M2-D, which came with LEDE OpenWRT v17.01. This stock firmware does not offer a lot of tweaking and, I was looking into installing ROOter (or OpenWRT) for this router but firmware is not available. Could you please kindly list steps on how you'd go about compiling firmware for this ZBT-Z2101AX router. Thanks in advance.

[Cruz40]

I have the zbt-z2101ax and was able to compile a Rooter build for it based on Rooter AB22: 22.03.2 was able to flash it through U-boot recovery. So far so good.

I recently purchased a ZBT model Z2101AX-M2-D, which came with LEDE OpenWRT v17.01. This stock firmware does not offer a lot of tweaking and, I was looking into installing ROOter (or OpenWRT) for this router but firmware is not available. Could you please kindly list steps on how you'd go about compiling firmware for this ZBT-Z2101AX router. Thanks in advance.

Do you know how to backup your current firmware?

I modified a compatible router .dts with my own and added system config to fix the lan ports and LEDs . The fix works on openwrt and rooter. I don't know how to submit a device add to openwrt. So I'll just link the files here in case someone wants to add the hardware to openwrt.

[GreyWolf23]

I am familiar with using, dd if=dev/mtdx of=/tmp/Factory.bin to back the firmware. On my other box, ZBT-WE826, which has Rooter installed in it, I was able to make a complete backup. But on this newer ZBT box, Z2101AX-M2-D, which, came with LEDE OpenWRT V17.01 - Snapshot, doesn't allowed me to use dd if=dev/mtd2 of=/tmp/RBackup/Factory.bin. If you know other ways, I would appreciate your help. Attached, screenshot of the router memory banks. By the way, where is the file you'd linked to the post?

[Cruz40]

I am familiar with using, dd if=dev/mtdx of=/tmp/Factory.bin to back the firmware. On my other box, ZBT-WE826, which has Rooter installed in it, I was able to make a complete backup. But on this newer ZBT box, Z2101AX-M2-D, which, came with LEDE OpenWRT V17.01 - Snapshot, doesn't allowed me to use dd if=dev/mtd2 of=/tmp/RBackup/Factory.bin. If you know other ways, I would appreciate your help. Attached, screenshot of the router memory banks. By the way, where is the file you'd linked to the post?

you want to use

dd if=dev/mtd3 of=/tmp/firmware.bin

this is the firmware

[Cruz40]

Firmware files and patches I've made this is for the ZBT-Z2101AX 4 port version 3xlan 1xwan

Modified Tenbay T-MB5EU v01 dts as its compadiable with ZBT-Z2101AX "4 port 3xlan 1xwan"
build was modified to "make -j13" for faster build on 12 core CPU
SYSTEM config edit for led fix

https://1drv.ms/f/s!Ao8qYENaIhxLlvJZ9rb ... w?e=jTGSm2

[GreyWolf23]

Thank you for posting your files. I am, now, able to back up the firmware from my router. Since I have never compiled ROOter using my own firmware, I would appreciate it if you could direct me how to do this.

[Cruz40]

Thank you for posting your files. I am, now, able to back up the firmware from my router. Since I have never compiled ROOter using my own firmware, I would appreciate it if you could direct me how to do this.

I've already compiled the firmware, it's in the link you don't need to recompile it. Put the unit into recovery mode to flash the rooter firmware bin full
Here is a link on how to install in recovery mode

https://openwrt.org/toh/zbtlink/wg2626

[lenn0x]

Firmware files and patches I've made this is for the ZBT-Z2101AX 4 port version 3xlan 1xwan

Modified Tenbay T-MB5EU v01 dts as its compadiable with ZBT-Z2101AX "4 port 3xlan 1xwan"
build was modified to "make -j13" for faster build on 12 core CPU
SYSTEM config edit for led fix

https://1drv.ms/f/s!Ao8qYENaIhxLlvJZ9rb ... w?e=jTGSm2

Thank you for this compile! currently running it on a Z2101AX-M.2-C. Hope this version get added to the autobuilds.

[GreyWolf23]

Thank you for posting your files. I am, now, able to back up the firmware from my router. Since I have never compiled ROOter using my own firmware, I would appreciate it if you could direct me how to do this.

I've already compiled the firmware, it's in the link you don't need to recompile it. Put the unit into recovery mode to flash the rooter firmware bin full
Here is a link on how to install in recovery mode

https://openwrt.org/toh/zbtlink/wg2626

I am currently running this ROOter firmware on my two ZBT routers, Z2101AX-M2-D and Z2101AX-M2-T, without issue. Thank you for sharing!

[Eric592]

Would one of you guys be willing to help me with at commands on rm520n-gl. iv made a post and haven't had any help yet but I keep getting a sim missing and iv looked can't find how to reset the modem to factory and start from scratch to see if it would finally connect.