Hi everyone there. I found out that USIM_VDD of my EG800Q-EU will go to 0V after some time. I followed exactly as the schematic given, but have no idea how to solve this issue. Does anyone face similar issue before?
This is the schematic from hardware design datasheet
These are the signal I captured using oscilloscope:
When detected SIM
The module did not recognize the SIM card. Suggest confirming according to the following description method：
1.The SIM card is functioning properly and can be verified on other devices such as mobile phones.
2. Ensure that the connection between the SIM card and the module is normal.
3. Measure the signals of all signal pins to determine if all SIM interfaces of the module are abnormal.
4. AT+CFUN? Confirm whether the RF parameters are normal based on feedback values is 1.
