suddenly cannot detect SIM

After a couple of weeks of installing Avast anti virus with the anti-theft function on a Samsung Galaxy mini, the cell phone cannot detect any SIM I put in it , even the original one.
So I decided to uninstall it, first deactivating as an admin device, and then uninstallink the Anti -theft program wihtout any error, but the cell phone still cannot detect any SIM card.
I have never received any alert in the friend cell phone that was configured to receive any message when anyone try to change the SIM.
What can i do to solve this?

this seems not to be a problem associated to avast, more like a hardware problem.