Hi @iran9374166620

Have you tried another known working, network compatible SIM card in your tablet to see if it works?

Have you tried your SIM card in a known working, network compatible device to see if it works?

Here is a link to the service manual for your tablet.

It shows the pre-requisites and procedures necessary to gain access to the components in your tablet.

https://download.lenovo.com/consumer/mob...

On p.42 item #8 it shows the part number for the SD Card/SIM card module. Check the number on your particular module and then search online using just the number, for suppliers of the part. It is not cheap!

Here is a link to just one supplier of the SD Card/SIM Card module to give you an idea of the cost.

http://electrical-components.com/lenovo/...

Hopefully this is of some help.