Invalid SIM Error is one common problem with the different modem models and brands by the different provider which comes as a result when the user attempts to insert a SIM card by a different provider for example Orange in the USB dongle from a different provider like Airtel. Its well known that the different mobile broadband/data service providers are known to have most of the modems/USB dongles locked to their carriers only as a result of one or the other reason for example, the need to keep their internet users on their networks and etc, and thus leading to the different error messages.
For many users out there with modems by the different providers have a high demand to have their data devices unlocked so that they can be used universally on any other network or provider SIM Card due to reasons like the ability to save, the need to use cheap data bundles, the need to access a wide range network coverage and many more others, and that is why in this tech guide, I will take you through the simple and easy but a guaranteed invalid SIM error solution so as to do whatever you need with your modem.
Before getting started, you need to know that the procedure below will require you to access some other external sites as you will discover below in order to get the other part of what you need to use for example the unlocking software in addition to having a different SIM card from another provider in order to test the results and below ewe go.
1. Check our your Modem model for example Huawei e1552, ZTE MF192, Alcatel.
2. Check on the back of the Modem to locate the IMEI number and note it down.
3. Now Visit any of the Modem/USB dongle unlock calculators, enter your Modem IMEI number, calculate the unlock code and save it down.
4. Now Visit any Modem Code Writer tool, download it, extract it and run it on your computer.
5. Click On Select Com Port, Choose the your modem and click on Unlock.
6. Enter the Unlock code calculated and your modem will be successfully Unlocked.
The reason why we use the Modem Code Writer tool is to allows the tool detect and remove the lock code since Invalid SIM error appears on modems whose dashboard don’t prompt for unlock code once you inset a card from a different provider.