Unresponsive RM520N-GL modem in X3000

Routers Cellular, USB modems
1

I ran these AT commands and now the modem doesn't expose /dev/ttyUSB2 or /dev/mhi_DUN or /dev/cdc-wdm0. The cellular interface in the web-ui also never loads. I'd be happy to supply any logs or outputs if anyone has any suggestions! /dev/ttyUSB0 and 1 are exposed but neither responds to AT, USB0 does nothing and USB1 hangs. Any info would be greatly appreciated, I'm happy to run any commands over ssh. Im currently thinking the only recovery route is removing the module and purchasing an adapter to connect it to a windows machine. Is there anything else I can try? Also would it be possible to reflash/debrick the modem directly from the router so i wouldnt have to purchase an adapter, I've read some about shorting two of the pads to get it in recovery mode which i am comfortable doing if the test pads are exposed on the module.

MODEM INFO

Module: RM520N-GL
Firmware: RM520NGLAAR03A03M4G_A0.303.A0.303

AT COMMANDS RAN

AT+QCFG="pcie/mode",1
AT+QCFG="data_interface",1,0
AT+QCFG="usbnet",3

LOGS

root@GL-X3000:~# dmesg | grep -i mhi
[ 11.996423] mhi_init Quectel_Linux_PCIE_MHI_Driver_V1.3.4

root@GL-X3000:~# dmesg | grep -i modem
[ 10.877959] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[ 12.174476] usbserial: USB Serial support registered for GSM modem (1-port)
[ 12.181673] option 1-1.2:1.2: GSM modem (1-port) converter detected
[ 12.188162] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 12.195268] option 1-1.2:1.3: GSM modem (1-port) converter detected
[ 12.201741] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[ 822.192269] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 822.205480] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 828.114684] option 1-1.2:1.2: GSM modem (1-port) converter detected
[ 828.121282] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 828.128766] option 1-1.2:1.3: GSM modem (1-port) converter detected
[ 828.135367] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1

root@GL-X3000:~# dmesg | grep -i usb
[ 0.177876] usbcore: registered new interface driver usbfs
[ 0.183442] usbcore: registered new interface driver hub
[ 0.188818] usbcore: registered new device driver usb
[ 0.462408] phy phy-usb-phy@11e10000.1: type_sw - reg 0x218, index 0
[ 0.495140] phy phy-usb-phy@11e10000.1: try to get sw efuse
[ 0.500743] phy phy-usb-phy@11e10000.1: try to get sw efuse+
[ 0.506454] phy phy-usb-phy@11e10000.1: u3 efuse - intr 29, rx_imp 10, tx_imp e
[ 1.085808] xhci-mtk 11200000.xhci: 11200000.xhci supply vusb33 not found, using dummy regulator
[ 1.094709] phy phy-usb-phy@11e10000.0: try to get sw efuse
[ 1.105690] xhci-mtk 11200000.xhci: new USB bus registered, assigned bus number 1
[ 1.128674] hub 1-0:1.0: USB hub found
[ 1.142028] xhci-mtk 11200000.xhci: new USB bus registered, assigned bus number 2
[ 1.149516] xhci-mtk 11200000.xhci: Host supports USB 3.2 Enhanced SuperSpeed
[ 1.156700] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 1.165132] hub 2-0:1.0: USB hub found
[ 1.173329] usbcore: registered new interface driver uas
[ 1.178730] usbcore: registered new interface driver usb-storage
[ 1.549902] usb 1-1: new high-speed USB device number 2 using xhci-mtk
[ 1.703588] hub 1-1:1.0: USB hub found
[ 1.997897] usb 1-1.1: new high-speed USB device number 3 using xhci-mtk
[ 2.106717] usb-storage 1-1.1:1.0: USB Mass Storage device detected
[ 2.113183] scsi host0: usb-storage 1-1.1:1.0
[ 3.814186] usbcore: registered new interface driver usb_ch343
[ 3.820031] ch343: USB serial driver for ch342/ch343/ch344/ch347/ch339/ch9101/ch9102/ch9103/ch9104/ch9143, etc.
[ 3.849773] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 3.871493] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 3.884453] uhci_hcd: USB Universal Host Controller Interface driver
[ 6.753897] usb 1-1.2: new high-speed USB device number 4 using xhci-mtk
[ 10.872283] usbcore: registered new interface driver cdc_acm
[ 10.877959] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[ 10.887344] usbcore: registered new interface driver cdc_wdm
[ 10.898848] usbcore: registered new interface driver ipheth
[ 12.011235] usbcore: registered new interface driver usbserial_generic
[ 12.017895] usbserial: USB Serial support registered for generic
[ 12.093923] usbcore: registered new interface driver cdc_ether
[ 12.102585] usbcore: registered new interface driver cdc_ncm
[ 12.109212] usbcore: registered new interface driver huawei_cdc_ncm
[ 12.129307] usbcore: registered new interface driver qmi_wwan
[ 12.145801] rndis_host 1-1.2:1.0 eth2: register 'rndis_host' at usb-11200000.xhci-1.2, RNDIS device, 0c:84:fd:cc:14:97
[ 12.156675] usbcore: registered new interface driver rndis_host
[ 12.168772] usbcore: registered new interface driver option
[ 12.174476] usbserial: USB Serial support registered for GSM modem (1-port)
[ 12.188162] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 12.201741] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[ 822.167336] rndis_host 1-1.2:1.0 eth2: unregister 'rndis_host' usb-11200000.xhci-1.2, RNDIS device
[ 822.192269] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 822.205480] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 828.102842] rndis_host 1-1.2:1.0 eth2: register 'rndis_host' at usb-11200000.xhci-1.2, RNDIS device, 0c:84:fd:cc:14:97
[ 828.121282] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 828.135367] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[ 828.143085] usb 1-1.2: authorized to connect
[ 850.597946] rndis_host 1-1.2:1.0 eth2: unregister 'rndis_host' usb-11200000.xhci-1.2, RNDIS device
root@GL-X3000:~#

2

Hi

Sorry for the late reply.

We spent some time testing this locally and consulting with Quectel.

For now, they recommend using an M.2 to USB adapter (such as our GL-M2) connected to Windows to resolve this issue.

Please note that opening the device will void the warranty.

We more recommend that you email cs@gl-inet.com with a brief description of the issue and a link to this post to seek assistance.

1 Like
4

Hello! No worries, thanks for the reply! I had already considered getting the m2 dev board, especially since the price seems quite reasonable. Although I believe it was out of stock the past few days, now when I look it says low stock, which is great! Yet when I try to checkout I get this error "This product is not available for delivery to your location." which is odd because my address is a residential address in town. I'm about to send an email and I'll provide the address I attempted to use, If we could figure out why it isn't working that would be great, But I could have it sent to another address if that's required.

5

Thank you for the update.

Regarding the shipping issue, yes, please contact us via email at cs@gl-inet.com. Our team will assist you further.

6

It seems the shipping issue was actually been a browser issue on my side. I was trying to get the m.2 dev board without the 5g module which seems to still be out of stock, so I will go with the ebay adapter so I can get it fixed. Seeing as there is no way around taking the router apart and removing the module, do you happen to have a guide on how to remove the module from the router? I've already taken the back off, yet the module is under a rather large heatsink and even after taking what I though was it's screw out it still seems rather stuck, I'd really like to not permanently the router, so any tips would be super helpful!

7

We don’t have a specific guide for this, so you may want to refer to steps shared by other users: