When this kind of message pops up on your mobile phone, the problem could be either from the Sim card or from the phone. The following steps will help you determine the source of the problem and subsequently help you deal with it.
Take the Sim card and try booting it in another phone while you also take another Sim from the same Network and try it on the phone. This simple step will determine where the problem is coming from.
You have to first make sure that the Sim Card is properly inserted with its gold plated contact/metallic chip seated on the Sim connectors in the phone. In other words, there must be proper alignment in the Sim Slot and locked where applicable.
A damaged sim card will present this problem. This may require a sim swap/replacement to solve the problem.
Sometimes when the sim card is getting old, worn out or abused this problem may present. SIM Swap Fraud In this case, placing a little folded piece of paper on the sim card before putting the battery may help. This will exert some pressure on the card, making it possible for it to have proper contact with sim connectors in the phone.
A dirty sim card could also be the problem. Cleaning with a soft piece of cloth moistened with mentholated spirit could be the answer. A pencil eraser could also be used for the cleaning. If some liquid got into the phone, the sim IC maybe damaged. Cleaning or changing the IC may solve the problem.
If the problem is with the phone, any of the following could do the trick
If phone is sim locked to a particular service provider, use the appropriate sim card or have it unlocked. If you can’t get the code to unlock it from the internet, take it to a certified technician.
You can also open the phone and look out for loose soldered parts around the connectors/sim card slot. If there is any, have it fixed by a certified technician.
This problem will arise if sim connectors are not properly aligned in the slot. Take a pin and pull up any that is out of alignment. Handset Simbase may require adjustment.
Check screws on the phone. If any is not tight, the board will not be able to read the sim card because proper contact is lacking between the sim card and the sim connectors on the phone.