SIM7600 works for several days, then stops responding or loses network registration until power-cycled

Projects Networking, Protocols, and Devices
1

Title

SIM7600 works for several days, then stops responding or loses network registration until power-cycled

Hi everyone,

I'm maintaining a remote computer vision system that has been deployed in the field. The system generally works well, but after running continuously for several days, the GSM/LTE modem occasionally stops functioning and the device can no longer communicate over the cellular network.

Hardware

  • Jetson Nano

  • SIM7600-series LTE/GSM module connected via USB serial

  • Solar-powered system with battery backup

  • Outdoor installation

Software

  • Python application

  • HTTP and SMS communication using AT commands

  • The software periodically checks:

    • SIM status

    • Network registration (AT+CREG? / AT+CEREG?)

    • Signal quality (AT+CSQ)

    • PDP context before starting communication

When communication fails, the modem may exhibit one or more of the following behaviors:

  • Stops responding to AT commands.

  • Loses network registration and never reconnects.

  • Communication times out indefinitely.

  • Recovers only after the modem is completely power-cycled.

I've already implemented software recovery methods, including:

  • Reinitializing the serial connection

  • AT+CFUN=0

  • AT+CFUN=1

  • Re-running the network registration sequence

These sometimes help temporarily, but eventually the same problem returns. A complete power disconnect is the only recovery method that appears to be consistently reliable.

My questions

For those who have deployed SIM7600 modules in unattended systems, what are the most common root causes of this type of long-term failure?

I'm particularly interested in whether the issue is more likely to be related to:

  • Power supply instability during LTE transmit bursts

  • Battery voltage drops under load

  • Thermal effects inside an outdoor enclosure

  • USB/serial interface lockups on Linux

  • SIM7600 firmware hangs or known firmware bugs

  • Network registration problems in weak-signal areas

  • Mobile operator or cellular network behavior

  • Long-running memory/resource issues

I'd also appreciate advice on:

  • The best diagnostic steps to determine the actual cause

  • Whether logging additional AT commands would help identify the failure

  • Whether a hardware watchdog or dedicated modem power switch is considered standard practice for reliable field deployments

  • Best practices for designing an automatic recovery strategy for an unattended device

If it would help with troubleshooting, I can provide:

  • AT command logs before and after the failure

  • dmesg logs from the Jetson

  • Power supply specifications and measurements

  • Antenna type and installation details

  • Signal quality history

  • Temperature/environmental conditions

  • The Python recovery code currently in use

I'd appreciate any suggestions from people who have experienced similar long-term reliability issues with the SIM7600 or similar LTE modules in production deployments.

2

could be many things

what about Brown Out Reset

do you monitor the solar Panel voltage?
GSM modems typically take about 2 amps when transmitting

assume when not transmitting you put the microcontroller into deep sleep and switch off all devices

have a look at post data-logging-and-solar-power for an example of using a Heltec WiFi32 LoRa V4 powered from a Heltec solar panel
however, LoRa uses far less power (typically 60mA) than GSM modems

3

Please check the power supply (the Solar-powered system with battery backup in your case). Maybe it cannot supply sufficient voltage or current.

4

It sounds like a power problem but without an annotated schematic showing the power sources and links to technical information on the components I cannot take a another guess at this point.