Q: My iPhone 5c show no service after I update it to iOS 9.3.1. Even on/off or restore it didn't help

Bought a phone from other person. it was okay that evening when I put in my sim car. When I wake up the next morning, it show no service. it has been a week since the no ser show. I swap my sim card to my sister iphone and it was okay. My uncle said that the sim tray was the problem. Please help