Modem Reboot Loop - EM7455,MC7455,EM-06

[h1353]

Hello,

I've been fighting an issue the past few days. Not going into details but I ended up damaging my RM520N-GL, and have resorted to some older hardware and setups while I'm waiting on new parts to arrive.

My Issue:
Router comes up, modem comes up, goes through what seems like a normal connection process, then "AT+CFUN=1,1" is issued. Which causes the EM7455 to power down and reboot.

Logs:

Code: Select all

Mon Jun 10 22:51:26 2024 : /dev/ttyUSB2 AT!SELRAT?
!SELRAT: 06, LTE Only
OK
  
Mon Jun 10 22:51:28 2024 : /dev/ttyUSB2 AT!ENTERCND="A710";!BAND?
Index, Name,                        GW Band Mask     L Band Mask      TDS Band Mask
11, Test,                           0000000000000000 0000000000000808 0000000000000000
OK
  

  
Mon Jun 10 22:51:30 2024 : /dev/ttyUSB2 AT!ENTERCND="AWRONG"
ERROR
  
Mon Jun 10 22:51:31 2024 : /dev/ttyUSB2 AT+CGMM
EM7455
OK
  
Mon Jun 10 22:51:32 2024 : /dev/ttyUSB2 AT!SELRAT?
!SELRAT: 06, LTE Only
OK
  
Mon Jun 10 22:51:45 2024 : /dev/ttyUSB2 at+cpin?
+CPIN: READY
OK
  
Mon Jun 10 22:51:46 2024 : /dev/ttyUSB2 AT!CUSTOM?
!CUSTOM: 
             GPSENABLE		0x01
             GPSLPM		0x01
             GPSSEL		0x01
             IPV6ENABLE		0x01
             UIM2ENABLE		0x01
             SIMLPM		0x01
             USBSERIALENABLE	0x01
             SINGLEAPNSWITCH	0x01
OK
  
Mon Jun 10 22:51:48 2024 : /dev/ttyUSB2 AT!GPSTRACK=x,xxx,x,xxxx
OK
  
Mon Jun 10 22:51:49 2024 : /dev/ttyUSB2 at!gpsloc?
Not Available
OK
  
Mon Jun 10 22:51:51 2024 : /dev/ttyUSB2 AT+COPS=3,2;+COPS?
+COPS: 0
OK
  
Mon Jun 10 22:51:53 2024 : /dev/ttyUSB2 AT+CGDCONT=?
+CGDCONT: (1-24),"IP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"PPP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV6",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV4V6",,,(0-2),(0-4),(0-1),(0-1)
OK
  
Mon Jun 10 22:51:54 2024 : /dev/ttyUSB2 AT+CGDCONT?;+CFUN?
+CGDCONT: 1,"IPV4V6","fast-t-mobile.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0
+CFUN: 1
OK

             IPV6ENABLE		0x01
             UIM2ENABLE		0x01
             SIMLPM		0x01
             USBSERIALENABLE	0x01
             SINGLEAPNSWITCH	0x01
OK

  
Mon Jun 10 22:51:58 2024 : /dev/ttyUSB2 AT+CMGS=?;+CMGL=?;+CMGR=?
+CMGL: (0-4)
OK
  
Mon Jun 10 22:51:59 2024 : /dev/ttyUSB2 AT+CMGF=0
OK
  
Mon Jun 10 22:52:01 2024 : /dev/ttyUSB2 at!gpsloc?
Not Available
OK
  
Mon Jun 10 22:52:03 2024 : /dev/ttyUSB2 AT+CPMS="SM","SM","SM"
+CPMS: 0,30,0,30,0,30
OK
  
Mon Jun 10 22:52:05 2024 : /dev/ttyUSB2 AT+CPMS="ME"
+CPMS: 0,255,0,30,0,30
OK
  
Mon Jun 10 22:52:07 2024 : /dev/ttyUSB2 AT+CFUN=1,1
OK

This also happens on a MC7455, and a Cradlepoint LP6 USB adapter(Connected to a GoldenOrb Router) thats configured with the correct USBCOMP. Tried QMI and MBIM

------------------------------------------------

I tried with some Quectel modems and LTEFIX USB m.2 sleds I have that are a year or two old. The process is about the same with the Quectel modems, except the reboot is initiated with "AT+QPOWD=1"

------------------------------------------------

I've tried 3 different builds of Golden ORB, March 2023, May 2024 and June 2024.

I've tried 2 different GL.Inet B1300s and a RPI3 flashed with GoldenOrb (Both 3/3023 and 2024 firmwares)

I've also tried keeping the Band Locking "Auto Restart" switch turned off, as I feel like its related, but possibly not.

------------------------------------------------

If I put the SIM in my Cradlepoint CB850 + LP6, it connects to the network immediately and I have internet service. This is the device I'm using at the moment, but I'd much rather use my GO Routers and LTEFix Modems and Sleds

Has anyone else seen or had this experience? Any suggestions?

[Didneywhorl]

Can you time the reboot? How long does it give until reboot?

There are like five different watchdogs in Rooter now, it is super super annoying.

1: Modem -> Connection Profiles -> Advanced Tab -> Disable Watchdog -> yes/no

2: Modem -> Connection Profiles -> Connection Monitoring Tab (usually off)

3: Modem -> Custom Ping Test (or something like that)

4: Some kind of internal Rooter watchdog I swear to gawd is there but I can't find it. You can see it go to work on the Modem logging page.

5: MWAN3 has some kind of watchdog as well, and it is only sometimes a problem, and I mean only with one WAN connection. I typically do not use the firmware image with MWAN3 unless I plan on using more than one WAN source FOR SURE. MWAN3 is in the firmware image with "full" in the file name.


Turn all off that you can find, and make sure you have a valid IMEI and APN for the SIM you are using. On the Sierra modems, make sure they aren't in Low Power Mode (AT+GSTATUS?) "LPM". If they are, reflash two times in a row with a Generic PRI image.


I was going to say it may be your modem, but if you have tried that many different modems with all the same effect, and different routers and firmware images, I'd say it's the watchdog in the firmware.