Quectel EC25 Mini PCIe USIM detection problem (USIM_VDD=0V)

[Robin_Xiao]

I tried to add i nthe 15k pull up resistor and made no improvement, the sim circuitry is exactly same asm refernce. So still stuck…

I did manage to speak with one of you company rep who explained that on boot logic. It detect sim with both 3V and 1.8V, for 3 times, if all 3 times failed, then VDD is shut off.

Still doesn’t explain why the Sim cant be detected

Anyone got any further ideas? Or anyone got any luck with a scope? I don’t have one.

@Kyson

Here’s another user with same issue

Quectel ec25 mini pcie sim detection problem

Hello every one, We use Quectel EC25 Mini PCIE, there are many devices at field. Some devices internet connection is lost. Even if device turn off and turn on, GSM module does not recognize simd AT+CPIN gives error or gives out put sim not ready. On order to recognize sim again, we need to take sim off and push it in again. When we check logs, its connected to GSM module, 1 minute later, GSM Module is not able to recognize SIM. Thank you…