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

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