SIM VCC issue Voltage issue

We designed custom hardware for HL7692 and facing SIM detection issue while testing found that SIM_VCC is not appearing.

  1. In MangoH after power ON HL7692 SIM_VCC 3V is appearing with or without sim.
  2. In Custom board after sim present or not present SIM_VCC is not appearing.
  3. With assumption of soldering issue we applied 3V on SIM_VCC line then voltage is dropping nothing but not soldering issue.

Can any one update SIM_VCC to appear any of the GPIO Pin operation should be there?
Can use external 3V supply for sim to operate.