Follow the steps below if the Iridium 9505A is displaying Check SIM or Insert SIM error.

Step 1: Remove SIM card 

1. Rotate the antenna on the phone away from the battery cover
2. Remove the battery cover by pressing down on the release clip located below the antenna socket and pulling the cover
3. Remove the battery by pressing down on the release clip located at the top of the battery
4. Unlock the SIM card door by sliding it to the left
5. Note the position of cut corner on the SIM card
6. Lift up the SIM card door
7. Remove SIM card
8. Obtain a soft cloth or contact cleaner
9. Wipe gold prongs on both SIM card and phone

Step 2: Insert SIM card

1. Insert SIM card into SIM card door
2. Ensure the cut corner of the SIM card lines up with the cut corner on the phone
3. Close SIM card door
4. Slide the SIM card door to the right to lock it in to place
5. Insert the battery and press firmly to lock it into place. Make sure the arrows on the battery are aligned with the arrows in the battery compartment
6. Insert the battery door and press firmly to lock it into place
7. Press and hold power button
8. The phone will power on and begin to search for the Iridium network