My EC200UCN is Unale to go to UArt Accept Mode I have Flashed it with the Firware still

IoT Modules LTE Standard Module
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Request for Official Firmware for EC200UCNAC-N05-SNNSA (UART Not Accepting AT Commands)

Dear Quectel Team,

I am requesting assistance regarding my EC200UCNAC-N05-SNNSA module.

I accidentally flashed a firmware build that seems to have UART locked. Currently, I am only able to send AT commands through the USB AT port, but the main UART interface does not accept any AT commands.

When I try to switch boot modes by shorting N_MODE or changing the startup mode, the device shows “device descriptor failed” on Windows and does not enter the expected download mode. Because of this, I cannot reflash the correct firmware.

Could you please provide:

  1. The latest official firmware for EC200UCNAC-N05-SNNSA,
  2. A version with UART unlocked (so the ESP32 can communicate normally),
  3. And any recommended flashing tools or steps for recovery?

This module is critical for my ongoing project with ESP32, so your help would be greatly appreciated.

Thank you very much, and I look forward to your support.

Best regards,

2

Hi @sudhanshu808 ，
Sent to your email, check pls.

3

after flashing the firware with q flash i get device desciption failed why so please help me with it

4

Pls take a screenshot.

5

Sir I have Mailed You in Here i am not Able to Share SS as New USer Please Check Your Email And Help me with my problem ### Module Information

  • Model: EC200UCNAC-N05-SNNSA
  • Flashed Firmware: EC200UCNAAR03A15M08
  • Power Source: 12 V → LM2596 (Output ~4.0 V)
  • Interface Used: USB

:wrench: What I Did

  1. Entered Download Mode by shorting BOOT to VDD_EXT

  2. Used QFlash (Unisoc) to flash firmware
    3.EC200UCNAAR03A15M08*

  3. Flashing completed successfully — QFlash showed PASS

  4. After flashing:

  • Removed BOOT–VDD short
  • Powered module OFF
  • Powered ON normally

:police_car_light: What Went Wrong

After rebooting the module in normal mode:

  • No USB ports enumerate

  • Windows reports:
    “Unknown USB Device (Device Descriptor Request Failed)”

    dm
    dm609×903 159 KB

  • No AT Port

  • No Modem/DIAG Ports

  • UART shows no boot logs

  • Module does not enter normal run mode

I also reinstalled the Unisoc drivers and reflashed the module again — flash again showed PASS, but the module still remains undetectable.

:camera_with_flash: Board Photos

:bar_chart: Voltage Measurements (While USB Connected & Module Powered)

USB Lines

Signal Voltage
D+ 1.77 V
D− 1.75 V

UART / Debug Lines

Signal Voltage
RX (board) 3.99 V
TX (board) 1.34 V
A_TX / A_RX 0 V
MAIN_RXD (EC200) 1.82 V
MAIN_TXD (EC200) 0.98 V

:electric_plug: Power / System Signals

Pin Name Voltage
VBAT_RF 4.02 V
VBAT_BB 4.02 V
STATUS 1.78 V
VDD_EXT 1.78 V
USIM_VDD 0 V
USB_BOOT 0 V
RESET_N 3.95 V
PWRKEY 0.20 V

:red_exclamation_mark: Summary of the Issue

Even though the firmware flash shows PASS, the module:

  • Does not start the bootloader
  • Does not load USB descriptors
  • Shows Unknown USB Device
  • Produces no UART output
  • Appears powered, but not executing ROM/boot code

It looks like the device may be stuck in a corrupted bootloader state, or the flashed firmware package may not be compatible with EC200UCNAC hardware.

6

Hi ,
May I ask which driver version you have

7

image
image1533×125 7.71 KB

i have above one installed