Problem: BG95 Mini PCIe not responding or blinking status LED

IoT Modules LPWA Module
1

Hi all,

I’m working with a Quectel BG95 Mini PCIe module on a custom board. The NET_STATUS LED does not blink, and I get no response to AT commands over UART.

What I’ve verified:

  • VCC_3V3 is stable at 3.3 V (measured on Mini PCIe pins 2/39/41/52)
  • PERST# is HIGH (3.3 V)
  • W_DISABLE# is tied to 3.3 V (not floating)
  • DTR is pulled LOW (confirmed at Pin 31)
  • Current draw jumps from ~50 mA to ~400 mA, suggesting the module is booting
  • Using FTDI USB-to-UART cable with settings: 115200 baud, 8 data bits, no parity, 1 stop bit, no flow control
  • Tried both QCOM and PuTTY, sending `AT

Symptoms:

  • NET_STATUS LED does not blink
  • No activity seen on BG95 TX(Pin 11) — line stays high at 3.3 V
  • I can see AT being sent on pin 13

Question:

What could prevent the BG95 Mini PCIe from blinking the NET_STATUS LED or responding over UART, even though current draw and power conditions suggest it is booting?

2

Hello @MrCricket55 ,

We have a similar problem on a BG95M3 module.

Like you, we have no response over UART. However, we have some other symptoms:

  • VDD_EXT is 2.4V instead of 1.8V → can you check if it’s the same for you?
  • Out STATUS pin toggles once every 2.5seconds. → can you check if that’s case for you too?

I feel like the module has a bad firmware and is not even booting.

I didn’t measure the current, but i see it spiking indeed, suggesting that something is hapenning.