Hello,
We have encountered an issue related to SIM detection in SC66 custom Boards 4 quantity.
We have designed these custom board and built over 200 units, recently, we built 4 more boards using the same hardware and firmware.
In these latest boards, we have encountered same issue with all 4 boards, where the SIM is not detected by the Android application in both slots.
We verified that the voltage at Pin - SIM USIM1_VDD is correctly at 1.78V.
Upon probing with oscilloscope, we see clock and data transaction happening during small duration only!
However, when we check through the AT cmd, the SIM card is detected as below logs but now also not detected in android.
We tried the following commands for SIM detection and network registration:
AT
OK
AT+CPIN?
+CPIN: READY
OK
AT+CREG?
+CREG: 0,6
OK
Kindly suggest the best solution to solve this issue.
Best regards
Pavan