KC868-A2 with SIM7600E – Unable to operate after multiple attempts

[panarosa]

1. Development Environment Setup
   • Arduino IDE (tested with both version 1.x and 2.x)
     
   • Official ESP32 core installed via URL:
     
     
     Code:

     https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
     
     
   • Selected board: ESP32 Dev Module
     
   • Baud rate set to 115200
     
2. Sketch Upload
   • Tested official KinCony sketches for KC868-A2 with SIM7600
     
   • Tested custom sketches for sending AT commands
     
   • Tested with PSRAM disabled to eliminate
     
     
     
   • Compilation and upload completed successfully → ESP32 is working correctly
     
3. Connections and Power Supply
   • KC868-A2 powered with 12V as per manual
     
   • LTE antenna connected to MAIN port of SIM7600 (not AUX/GNSS)
     
   • Verified presence of power and indicator LEDs:
     • Red power LED solid on
       
     • Green modem LED blinking continuously
       
4. SIM Cards
   • Tested two different SIM cards in two different SIM7600E modules → no response
     
   • SIM cards confirmed working in a mobile phone
     
   • SIM PIN disabled
     
   • Contacts cleaned
     
   • Correct insertion verified
     
5. AT Command Tests from ESP32
   
   → no response
   
6. Serial Monitor shows nothing or “modem not found”
   
7. Alternative Checks
   • Attempted direct connection via USB MODEM to PC (drivers not easily available)
     
   • Tried alternative SIM slots and different LTE antennas
     
   • Evaluated alternative GSM modules (SIM800C, SIM800L) → working in other projects
     
   • Conclusion:
     The ESP32 works and communicates correctly via USB, but the SIM7600E module does not respond to any AT command, even after testing with two different units, proper power supply, and a suitable LTE antenna.
     

[admin]

already repied in another thread.